1. Intro- The Ice Age in Utah
18,000 years ago in Utah
The Ice Age in Utah
The landscape and life in Utah during the most recent Ice Age in Utah 10,000 to 30,000 years ago.
Salt Lake City
Lake
Bonneville
glaciers
During the most recent Ice Age in Utah, glaciers blanketed the mountains and Lake Bonneville covered most of Utah’s western valleys. Habitats suitable for mammoths, mastodons, camels, horses, muskoxen, long-horned bison, and saber-toothed cats, were restricted to the margins of Lake Bonneville and the periphery of mountain glaciers. Climate effects during the Ice Age became drastic by the end of the Pleistocene. There was a net loss of plant and animal diversity and ultimately mastodons, mammoths, camels, horses, ground sloths, and many other species became extinct. The extinction of these Pleistocene animals is not well understood. Two main theories are the “Pleistocene Overkill Theory”, which states that large animals were killed off by early humans, and the “Climate Theory” which holds that large animals failed to adjust to rapid climate changes.

2. Ice Ages Throughout Geologic Time
Quaternary
Ice Ages Throughout Geologic Time
Figure modified after C.R. Scotese
PALEOMAP Project (
Ice Ages Throughout Geologic Time
The Quaternary Period is the latest period of geologic time. It is made up of two epochs, the Pleistocene and the Holocene, or present. The Pleistocene Epoch is Earth’s most recent Ice Age. An ice age is a long period of time when temperatures are relatively cold and large areas of the Earth are covered by ice. The time that we typically think of as the “Ice Age” peaked about 18,000 years ago during what is called the Last Glacial Maximum. We are presently living in an interglacial, or warm period, between glacial episodes in the current ice age that began about 3 million years ago (Pleistocene Epoch).
Ice ages have occurred numerous times throughout geologic time. Major ice ages occurred during the Precambrian (~ million years ago), the Ordovician to Silurian (~ million years ago), the Carboniferous to Permian (~ million years ago), and the Pleistocene to Holocene (~3 million years ago to present).
12°
22°
17°
Average Global Temperature (0C)

3. Last Glacial Maximum 18,000 years ago
C.R. Scotese, PALEOMAP Project, (
Last Glacial Maximum 18,000 years ago
During the Last Glacial Maximum, continental ice sheets covered a large part of the Earth. Notice that most of Canada, Greenland and Scandinavia were under ice. In the United States, ice sheets covered the Great Lakes region and mountain glaciers existed in the western mountain ranges.

4. Obliquity (Axial Tilt) 41,000 years
Milankovitch Cycles
Eccentricity
90,000 to 100,000 years
Precession
19,000 to 23,000 years
~5%
~0%
Milankovitch Cycles
Variations in the Earth's eccentricity, obliquity (axial tilt), and precession, collectively known as the Milankovitch Cycles, affect the amount of solar radiation the earth receives and therefore are responsible for major changes to the earth's climate (even ice ages). Eccentricity describes the shape of the earth’s orbit around the sun. This constantly fluctuating, orbital shape ranges between more and less elliptical (0 to 5% ellipticity) on a cycle of approximately 100,000 years. At present the orbital eccentricity is nearly at the minimum ellipticity. Obliquity (axial tilt) is the inclination of the Earth's axis in relation to its plane of orbit around the sun. Oscillations in the degree of Earth's axial tilt from 21.5 to 24.5 degrees occur on a periodicity of 41,000 years. At present, the tilt is decreasing and is at degrees. Precession is the Earth’s slow wobble as it spins on its axis. The earth completes one wobble every 21,000 years.
Obliquity (Axial Tilt) 41,000 years
Figures modified after Matt Beedle, Montana Sate University.

5. Lake Bonneville and Ice Coverage in Utah During the Late Pleistocene ~18,000 years ago
Uinta Mountains
Lake Bonneville and Ice Coverage in Utah During the Late Pleistocene ~18,000 years ago
This map shows Lake Bonneville and the maximum extent of ice coverage in Utah about 18,000 years ago. Notice the broad expanse of ice that covered the Uinta Mountains! The Wasatch Range also underwent some glaciation during the most recent ice age. The power of these large glaciers hundreds of feet thick left their mark on the mountainous landscape of the Wasatch, creating most of the beautiful mountain scenery we have today. The cooler, wetter climate in the late Pleistocene caused Lake Bonneville to rise to its maximum level and large amounts of snow and ice to accumulate in mountainous regions.
Wasatch
Range

6. Lake Bonneville ~18,000 years ago
Salt Lake
Lake Bonneville ~18,000 years ago
Regional map of Lake Bonneville at its highstand about 18,000 years ago. Note that Lake Bonneville extended across most of northwestern Utah and into parts of Idaho and Nevada.
Delta
Utah

7. The Rise and Fall of Lake Bonneville
Provo Level
17,000 years ago
Great Salt
Lake today
Bonneville Level
18,000 years ago
Gilbert Level
12,000 years ago
The Rise and Fall of Lake Bonneville
The hydrograph for Lake Bonneville represents lake levels over the past 24,000 years. Maps of Lake Bonneville (background) indicate when the four major shorelines were formed; Stansbury, Bonneville, Provo and Gilbert. The location of present-day Great Salt Lake is depicted in dark blue.
Hydrograph of Lake Bonneville
Stansbury Level
24,000 years ago

8. Stansbury Shoreline ~ 24,000 years ago
Ogden
Delta
Nephi
Provo
Salt Lake UT ID NV
Red Rock Pass
Stansbury Shoreline
~24,000 years ago
Stansbury Island
Stansbury Shoreline ~ 24,000 years ago
This map shows the Stansbury level of Lake Bonneville about 24,000 years ago. At this time, cooler and wetter climate conditions caused the lake to begin to rise from a level close to that of the present-day Great Salt Lake. The Stansbury shoreline, the oldest of the four major shorelines, actually formed during the transgressive phase of Lake Bonneville as the lake was rising. The Stansbury shoreline is usually difficult to see, but can be spotted (from I-80) on the south end of Stansbury Island.

9. Bonneville Shoreline ~18,000 years ago
Red Rock Pass UT ID NV
Bonneville Shoreline
~18,000 years ago
Ogden
Delta
Nephi
Provo
Salt Lake
Point of the Mountain
Bonneville Shoreline ~18,000 years ago
This map depicts Lake Bonneville about 18,000 years ago. This is the highest stage of Lake Bonneville and at this time the lake level was controlled by a threshold near Red Rock Pass, Idaho. About 17,500 years ago, the threshold broke and water spilled out catastrophically into the Snake River drainage. This event is called the Bonneville flood. It is estimated that in less than one year, the amount of water that flowed out of Lake Bonneville was equivalent to all of the freshwater flowing in the world today!
One of the best places to view the Bonneville shoreline is at Point of the Mountain in Draper, Utah. The flat bench extending from Point of the Mountain to the east was formed by waves and currents in Lake Bonneville.

10. Provo Shoreline ~17,000 years ago
Red Rock Pass UT ID NV
Provo Shoreline
Ogden
Delta
Nephi
Provo
Salt Lake
~17,000 years ago
Provo Shoreline ~17,000 years ago
This map shows the Provo level of Lake Bonneville about 17,000 years ago. During the Bonneville flood, the lake dropped about 340 feet to the Provo level where it remained for approximately 2,500 years.
The Provo shoreline is one of the most visible shorelines in the Bonneville basin and is commonly covered by a calcium carbonate deposit called tufa (see slide #19 for a description of tufa).

11. Gilbert Shoreline ~12,000 years ago
Ogden
Delta
Nephi
Provo
Salt Lake UT ID NV
Red Rock Pass
Gilbert Shoreline
~12,000 years ago
Gilbert Shoreline ~12,000 years ago
This map depicts the Gilbert level of Lake Bonneville about 12,000 years ago. About 14,000 years ago, the climate became warmer and drier and the lake level began to drop. Some evidence exists that the lake almost completely dried up before rising to the Gilbert level about 12,000 years ago.
The Gilbert level is difficult to see because it is only about 50 feet higher than the current Great Salt Lake and is covered in many places by buildings and roads.

12. Great Salt Lake Today ID NV UT Ogden Salt Lake Provo Nephi Delta
Red Rock Pass
Great Salt Lake Today
Great Salt Lake Today
This map depicts present-day Great Salt Lake. Great Salt Lake is the largest remaining remnant of Lake Bonneville. Other relics of Lake Bonneville are Utah Lake, Sevier Lake, and the Great Salt Lake Desert containing the famous Bonneville Salt Flats. The chemical composition of Great Salt Lake is similar to that of typical ocean water. Sodium and chloride are the major ions in the water, followed by sulfate, magnesium, calcium, and potassium.  Although much of the salt contained in the Great Salt Lake was originally in the water of Lake Bonneville, a small amount of dissolved salts is deposited in the lake every year by rivers and numerous small streams that feed into it. As the lake rises, its salinity drops because the same amount of salt is dissolved in more water. In historical time, the lake's salinity has ranged from a little less than 5% (just above that of sea water) to nearly 27% (beyond which water cannot hold more salt).

13. Shorelines of Lake Bonneville at Antelope Island
Provo
Unnamed shoreline
Stansbury
Shorelines of Lake Bonneville on Antelope Island
Well-defined shorelines are visible at Buffalo Point on the northwest side of Antelope Island. Notice that there are more than four shorelines present. Dozens of unnamed shorelines associated with the oscillations of Lake Bonneville can be seen around the Bonneville basin.
Gilbert
Unnamed shoreline

14. Bonneville Shoreline at Point of the Mountain
Bonneville Shoreline at Point of the Mountain (view to the southwest)
This once pristine shoreline near Draper, Utah, is now the site of subdivisions and an expanding gravel pit. The site is also a popular hang gliding and paragliding launch spot. Note the paragliders flying above the ridge on the inset to the right. With increasing building and excavation in this area, pilots are running out of places to land!
Paragliders

15. Bonneville Shoreline at Point of the Mountain
Bonneville Shoreline at the “U”
Bonneville Shoreline at the “U” and Point of the Mountain
These are two good spots to view the Bonneville shoreline. At the University of Utah, the Bonneville shoreline forms the bench just under the “U” on the mountainside. This bench is the site of the popular Bonneville Shoreline Trail that is frequented by hikers and mountain bikers.
The Bonneville shoreline is still somewhat intact on the south side of Point of the Mountain and can be seen looking north from I-15.
Bonneville Shoreline at Point of the Mountain

16. Lake Bonneville Barrier Bar and Spit Modern Barrier Bar and Spit
Kiawah Island, South Carolina
Lake Bonneville
Barrier Bar and Spit
Lake Bonneville Barrier Bar and Spit
(view to the north, from highway SR 36)
The lower photo is of the Stockton Bar, located in Tooele County, Utah. The Stockton Bar is a composite of barrier bars and spits that formed in Lake Bonneville when it was near its highest level. The Stockton Bar formed much in the same way as the modern barrier bar and spit at Kiawah Island, South Carolina.
A spit forms when sediment is transported along a shoreline and is deposited in a fingerlike extension into a body of water. A barrier bar is simply a spit that has extended all the way across a body of water and has become attached to the shoreline on both ends.
Modern Barrier Bar and Spit
Stockton Bar, Utah

17. Lake Bonneville Spits Younger spit Contact surface Older spit
This picture shows a younger spit that has built out over an older spit near Fish Springs, Juab County, Utah. Note the different angles at which the sediments were deposited. The older spit is made up of horizontal (flat lying) layers that indicate that lake level was rising about as fast as sediment was being deposited. The steeply dipping beds of the younger spit indicate that sediment was accumulating faster than the lake was rising during this time.
Older spit

18. Lake Bonneville Deep-Water Sediments
Laminations
Lake Bonneville Deep-Water Sediments
Most sediments in deep water are very fine-grained silt and clay and settle very slowly to the lake bottom. Many of these deposits are finely layered (laminated), indicating a change in lake chemistry or sediment input.

19. Tufa on the Provo Shoreline
This is a view of tufa on the Provo shoreline near Delta, Utah. Tufa is a hard coating made of calcium carbonate that covers rocks and sediments. It formed when the concentration of dissolved solids in the lake increased due to a decrease in lake level. Tufa is easy to spot because it looks like a pile of concrete that has been dumped out of a cement truck!
Tufa on Quartzite

20. Lake Bonneville Delta at Rock Creek, Utah County
Sediment Transport
Direction
Lake Bonneville Delta at Rock Creek, Utah County
(view to the northwest)
Deltas form when sediments carried by rivers and streams are deposited into a standing body of water (lake or ocean). Rock Creek delta was formed in Lake Bonneville as sediments were transported down American Fork Canyon and dumped into the lake. The layers of sand and gravel are dipping toward the center of the valley (to the west), where the deepest part of the lake was located.

21. Provo Shoreline Wave-Cut Platform
This wave-cut platform is located on the Provo shoreline near Lucin, Utah. The platform (a bedrock terrace left behind by the receding cliff) was formed by strong currents and waves eroding away the hard rock that forms the cliff in the center of the photo.
Wave Direction

22. Bonneville Salt Flats Bonneville Shoreline Provo Shoreline Salt
The Bonneville Salt Flats can be seen from I-80 near Wendover, Utah. When Lake Bonneville evaporated, salt from the water was left behind on the dry lake bed. The Bonneville Salt Flats are one of the flattest areas on earth and are the site of many land-speed records set by race cars.
In the background, the Bonneville and Provo shorelines can be seen on the Silver Island Range.
Salt

23. Modern Glaciers Alaska
Most of the large continental ice sheets have disappeared since the Last Glacial Maximum about 18,000 years ago, but many mountain glaciers still exist around the world. These images depict two glaciers in Alaska; the Devil’s Desk Glacier that perches high on a mountainside, and the Halo Glacier that extends down to sea level.
Devil’s Desk Glacier
Halo Glacier, Cook Inlet

24. Holgate Glacier, Alaska
Holgate Glacier, Kenai Peninsula, Alaska
This glacier on the Kenai Peninsula is one of several glaciers from the Harding Icefield. Can you picture what the valley looks like beneath the glacier?

25. Sierra Nevada Mountains
Glacial Cirques
Uinta Mountains
Glacial Cirque
Glacial Cirques
A cirque is formed when a glacier scours out a semi-circular basin on a mountainside. The upper photo shows a cirque in the Uinta Mountains, which were extensively glaciated during the last glacial episode (~ 18,000 years ago). Convict Lake occupies another late Pleistocene glacial cirque that formed in the Sierra Nevada Mountains.
Glacial Cirque
Convict Lake,
Sierra Nevada Mountains

26. U-shaped Glacial Canyons
Yosemite Valley
Little Cottonwood Canyon
U-shaped Glacial Valleys
When a glacier moves down a valley/canyon, it erodes and scours everything in its path. After the glacier recedes, a characteristic “U-shaped” valley is left behind.
Glacier National Park

27. Mill Creek Canyon “V-shaped” Stream- eroded canyon
Little Cottonwood Canyon “U-shaped” Glacier- eroded canyon
“U-shaped” and V-shaped” Valleys
Little Cottonwood Canyon displays the characteristic U-shape of glacially carved valleys/canyons. Mill Creek Canyon, in comparison, is V-shaped, which is typical of valleys formed mainly by stream erosion.
Mill Creek Canyon “V-shaped” Stream- eroded canyon

28. Glacial Scenery at Alta, Utah
Arêtes
U-shaped
Valley
Glacial Scenery at Little Cottonwood Canyon
During the last ice age (~ 18,000 years ago), glaciers advanced down Little Cottonwood Canyon to the canyon mouth. The glaciers scoured the canyon floor and walls, leaving behind a classic “U – shaped” valley that is characteristic of glacial erosion. Glacially carved canyons typically have steep, smooth walls. Arêtes are sharp, knife-edge ridges that are formed when two glaciers erode adjacent tributary canyons.
Glacial Scenery at Alta, Utah

29. Moraines Chugach Mountains, Alaska
Medial Moraine
Moraines, Chugach Mountains, Alaska
A glacial moraine is a ridge of rock and debris that has been scoured and “bulldozed” by a glacier. Lateral moraines form on the sides of glaciers, medial moraines form when lateral moraines from two or more tributary glaciers merge, and terminal moraines form at the ends of glaciers. This unnamed glacier is just one of many glaciers that are retreating in Alaska's Chugach Mountains. The elevated medial moraine is a sign of retreat.
Image by Bruce Molnia, Terra Photographics
Image by Michael Collier

30. Glacial Features at Little Cottonwood Canyon
Trimline
Moraines
Glacial Features at Little Cottonwood Canyon, Salt Lake County
Several characteristic glacial features, including moraines and the U-shaped valley, can be seen at the mouth of Little Cottonwood Canyon. A trimline (here seen as a change from a smooth slope to a steeper, more rugged slope) marks the maximum upper level of the margins of a glacier. The fault scarps formed when large earthquakes occurred on this portion of the Wasatch fault.
U-Shaped Valley
Fault Scarps

31. Bells Canyon, Salt Lake County, Utah
Bells Canyon, Utah
Lateral
Moraine
Fault
Scarp
Bells Canyon, Salt Lake County, Utah
The ridge seen in the middle of this picture is a lateral moraine that formed as a glacier moved down Bells Canyon. Large earthquakes formed the fault scarp that shows as a break in slope on the moraine.

32. Denali National Park, Alaska
Glacial Erratics
Voyageurs National Park, Minnesota
Glacial Erratics
Erratics are rock fragments that have been carried by glacial ice and deposited some distance from their original source. Erratics can be as small as a pebble to as large as a house! Note the person in the lower photograph for scale.
Denali National Park, Alaska
Person

33. Little Cottonwood Canyon
Little Cottonwood Canyon Glacial Erratics
Many erratics are located near the mouth of Little Cottonwood Canyon. The erratic in the lower photo was the popular “painted rock” near the intersection of 9400 South and Wasatch Boulevard. This photo was taken in April of 2002 and the rock has since been removed to make way for a new housing development.
Glacial Erratics

34. Glacial Polish and Grooves
Grooves and polish on bedrock
Glacier National Park, Montana
Glacial Polish and Grooves
Glacial ice contains a lot of rock fragments and debris that help to erode bedrock at the base and sides of a glacier. Small fragments such as sand tend to polish and smooth the surface of the bedrock. Larger pebbles can carve out parallel striations or grooves on the bedrock as they move along with the ice.
Striations

35. Life in Utah During the Ice Age
Most of what we know about life in Utah during the Ice Age is based on fossils found in Lake Bonneville shoreline deposits. These fossils date from approximately 20,000 – 10,000 years ago, which is also the time of the latest period of glaciation at the very end of the Ice Age. Ice Age fossils are found in Utah right up until the time of the Pleistocene Extinction.
New discoveries of fossil vertebrates in Utah provides us with some information about some of the many animals that lived here during the Ice Age. A nearly complete skeleton of the Colombian mammoth, Mammuthus columbi, along with plant fossils, and an associated cheekbone with teeth of the giant short-faced bear, Arctodus simus, was discovered by construction crews in Huntington Canyon, between Fairview and Huntington, Utah in Two other mammoth sites were discovered in 1995: The complete lower jaw of a baby mammoth was found along with the skeletal remains of a muskoxen at Bear Lake, Utah, and construction workers discovered the complete tusk of an adult mammoth about 7 feet long and nearly a foot in diameter near Logan, Utah.
Other Ice Age fossils from Utah have been found in cave deposits of southern and western Utah; and Utah’s only early Ice Age fossils, which are about one million years old, from Little Dell Reservoir just east of Salt Lake City.

36. Life in Utah at the end of the Ice Age
This is a scene from the Ice Age mural by Joseph S. Venus at the College of Eastern Utah Prehistoric Museum in Price, Utah. It is a reconstruction of Ice Age life found in Utah.

37. Assorted Lake Bonneville Mollusks
Lake Bonneville supported various species of clams and snails. Some species still exist in small isolated populations in streams and springs. The photo above displays some of these species found in Lake Bonneville sediments. Gastropods (Snails): Stagnicola, Stuccinea, Physella, Planorbella, Valvata, Gyraulus; Bivalves (Clams & Oysters): Anodonta.

38. Hunting for Gastropods (Snails)
Here, a research group is searching for gastropod (snail) shells near the Deep Creek Mountains in western Utah. Scientists often use fossils as indicators of environmental conditions (e.g. salinity, temperature, light penetration, etc.) and for radiocarbon dating.
Also shown is a close-up view of Pyragalopsis sp. and Stagnicola bonnevillensis, two common species of snails found in Lake Bonneville sediments. These snails lived in the quiet, relatively shallow waters of Lake Bonneville and fed off of algae growing on the lake-bottom sediments. .

39. Bonneville Cutthroat Trout
Today are isolated in streams that once drained into Lake Bonneville.
Bonneville Cutthroat Trout
The Bonneville cutthroat trout, (Oncorhynchus clarkii utah) is a subspecies of the cutthroat trout native to the Bonneville Basin of Utah, Wyoming, Idaho, and Nevada 30,000 years ago. Today, the Bonneville cutthroat trout live in more restricted populations and are found in isolated streams that once drained into Lake Bonneville.
In the past decade a tremendous effort has been underway to bring back the native Bonneville cutthroat populations. In 1978 only six remaining populations of Bonneville cutthroat trout were known to exist in Utah, and they occupied less than five stream miles. By 2001, Division of Wildlife Resources biologists estimated at least 166 populations existed along 630 miles of streams.
Known Distribution

40. Utah’s Giant Ice Age Birds
Teratornis-
“giant condor”
Utah’s Giant Ice Age Birds
The teratorns are closely related to vultures and condors, which were also found in large numbers in the Great Basin during the Ice Age. These impressive giant birds had a wingspan of roughly feet or more and weighed 35 pounds. They had a hooked, somewhat eagle-like beak. The decline of the condors, teratorns, and vultures in western North America sometime toward the end of the last Ice Age coincides with the extinction of large mammals such as mastodons, giant sloths, camels, and saber-toothed cats that these giant birds fed on.
The California condors are among the largest flying birds in the world. Adults weigh approximately 22 pounds and have a wing span up to 9½  feet. During the late Pleistocene the condor could be found in great numbers all over the southwestern United States. Currently the California condor is endangered and a recovery program is underway to re-establish the species through captive breeding. Today condors are being reintroduced into the mountains of southern California, the central California coast, and near the Grand Canyon in Arizona.
Teratornis skeleton
Endangered California Condor
Teratornis skull

41. Ice Age Land Bridges and Mammal Migrations
Mammoths, mastodons, and bison migrated from Eurasia to North America. Camels and horses migrated from North America to Eurasia. Camels, deer, rabbits, rodents, dogs, and cats migrated from North America to South America. Ground sloths, porcupines, and armadillos migrated from South America to North America.

42. Ice Age Elephants Mammoth Mastodon The Huntington Mammoth
Ice Age Elephants - Mammoths and Mastodons
Mammoths (Mammuthus) and mastodons (Mammut), members of the order Proboscidea, are extinct relatives of living elephants that were common throughout the Ice Age of North America. The mastodons evolved in Africa about 35 million years ago and spread throughout Africa, Europe, and Asia. About 3.7 million years ago mastodons migrated to North America via the Bering Land Bridge. The mammoths appeared in sub-Sahara Africa about 3-4 million years ago, migrated across Europe, Asia, and Berengia, and eventually crossed over the Bering Land Bridge into North America about 1.7 million years ago. Both the mastodon and mammoth became extinct at the end of the Ice Age, about 10,000 years ago.
Mammoth Mastodon
The Huntington Mammoth
(Mammathus columbi) skeleton at the CEU Prehistoric Museum
Detail from Joseph S. Venus mural, College of Eastern Utah (CEU) Prehistoric Museum, Price, Utah

43. Mammoth & Elephants vs. Mastodons
Elephants and mammoths have high skulls, while mastodons have low skulls.
Columbian Mammoth (M. columbi)
Mammoths & Elephants vs Mastodons
Columbian mammoths (Mammathus columbi), a species adapted to open habitats, have been found from the northern reaches of North America into Mexico. The Columbian mammoth was a descendent of Mammuthus meridionalis, the ancestral mammoth that entered North America via the Bering Land Bridge about 1.7 million years ago. Mammoths are more closely related to modern elephants than mastodons. North American mammoths had flat, high-crowned teeth, well suited for the grinding of grasses. Their distribution also reflects this; their remains are most abundant in the rocks and sediments of open grasslands. They could reach a height of 11 feet at the shoulder (comparable to the size of an African elephant).
The American mastodons (Mammut americanum) roamed North America from at least 3.7 million to 10,000 years ago. Mastadons’ teeth were pointed, enamel-covered cones, well suited for their diet of herbs, shrubs, and tree bark. Unlike mammoths these animals were browsers living in open woodlands. They were massive, stockier in build than mammoths and modern elephants. They were also shorter, standing about 9 to 10 feet at the shoulder.
American Mastodon (Mammut americanum)
Elephants and mammoths have low, highly enfolded teeth for grazing, while mastodons have high crested teeth for browsing leaves.
Elephants and mammoths are tall, while mastodons are shorter with more massive bodies.

44. Saber-toothed Cat Skeletal reconstruction and detail from
The saber-toothed cat (Smilodon) from the Late Pleistocene was the size of a lion and had enlarged canines that looked like small elephant tusks. Unlike lions, which have long tails that help provide balance when the animals run, Smilodons had bobtails which suggests that they probably did not chase down prey, but charged from ambush instead, waiting for prey to come close before attacking. The saber-toothed cat went extinct about 10,000 years ago. A few bones of the species Smilodon californicus have been found near Park City.
Smilodon fatalis
Skeletal reconstruction and detail from
Joseph S. Venus mural, CEU Prehistoric
Museum, Price, Utah

45. Giant Ground Sloth
Giant Ground Sloth
The extinct giant ground sloths of North America, relatives of the modern South American tree sloths, migrated from South America during the late Pleistocene. Two species of ground sloth lived in Utah during the Ice Age. Jefferson’s ground sloth (Megalonyx jeffersoni), named after the third President of the United States, Thomas Jefferson, was the size of a bison. Harlan’s ground sloth (Glossotherium harlani) was larger than the Jefferson’s ground sloth and had small pebble-like bones under its skin, which may have served as armor against predators.
Skeletal reconstruction and detail from Joseph S. Venus mural, CEU Prehistoric Museum, Price, Utah

46. Other Extinct Ice Age Mammals
Camel, horse (not pictured), long-horned bison, and musk ox fossils have all been found in Utah. Horses evolved in North America and crossed into Asia via the Bering Land Bridge. They became extinct at the end of the Ice Age, only to be reintroduced by European settlers. Camels, like horses, are also New World natives that evolved here and entered Asia via the Bering Land Bridge. Unlike horses, however, some of the camel family – llamas, survived the Ice Age. Bison evolved in Eurasia and migrated to North America near the end of the Ice Age. Two extinct species of long-horned bison found in Utah are close relatives of our modern bison. The helmeted musk ox (Bootherium bombifrons) was one of five different kinds of muskoxen that lived in North America during the Pleistocene. However, it appears to have been the only one to have evolved and remained restricted to North America. It is the most common mammal fossil found along the shores of ancient Lake Bonneville. Two new sites have produced partial skulls of these muskoxen. One is from a gravel pit near the Kennecott Copper Mine west of Salt Lake City, and the other is from the construction site of the Huntsman building at the University of Utah.
Extinct Long-Horned Bison
Extinct Musk Ox
Camels, together with native horses, went extinct in North America at the end of the Ice Age

47. Mountain mammals that lived in Ice Age Lowlands
Fossil records provide evidence that mammals that now seem confined to isolated mountain ranges in the Great Basin were widespread in low elevation settings toward the end of the Pleistocene. In addition to documenting range limits, the fossil record also shows the prehistoric abundances of these species. This is particularly true of the American pika whose fossils are found in enormous numbers. Today, the American pika are found in some of the high mountain ranges of Utah, where it prefers rocky slopes above the treeline. The wolverine lived during the Ice Age in small numbers (and still may be found) in the high mountainous areas of the state. Wolverines prefer alpine tundra and mountain forest habitats that are not frequented by humans.
The wolverine, Gulo gulo
The American pika, Ochotona princeps,

48. Power Point Presentation (list of slides)
1. Intro – the Ice Age in Utah
2. Ice Ages Throughout Geologic Time
3. Last Glacial Maximum 18,000 years ago
4. Milankovitch Cycles: Changes in Earth’s Orbit
5. Lake Bonneville and Ice Coverage in Utah ~ 18,000 yrs ago
6. Lake Bonneville ~ 18,000 years ago
7. The Rise and Fall of Lake Bonneville
8. Stansbury Shoreline ~ 24,000 years ago
9. Bonneville Shoreline ~ 18,000 years ago
10. Provo Shoreline ~ 18,000 years ago
11. Gilbert Shoreline ~ 12,600 years ago
12. Great Salt Lake - Today
13. Shorelines of Lake Bonneville on Antelope Island
14. Bonneville Shoreline at Point of the Mountain
15. Bonneville Shoreline at “U” and Point of the Mountain
16. Stockton Bar, Utah
17. Lake Bonneville Spits
18. Lake Bonneville Deep Water Sediments
19. Tufa on the Provo Shoreline
20. Lake Bonneville Delta
21. Provo Shoreline Wave Cut Platform
22. Bonneville Salt Flats
23. Modern Glaciers - Alaska
24. Holgate Galcier, Alaska
25. Glacial Cirques
26. U-shaped Glacial Canyons
27. “U-shaped” and “V-shaped” Canyons
28. Glacial Scenery at Alta, Utah
29. Moraines on the Juneau Icefield, Alaska
30. Glacial Features at Little Cottonwood Canyon, Utah
31. Bells Canyon, Utah
32. Glacial Erratics
33. Little Cottonwood Canyon Glacial Erratics
34. Glacial Polish and Grooves
35. Life in Utah during the Ice Age
36. Life in Utah at the end of the Ice Age
37. Assorted Lake Bonneville Mollusks
38. Hunting for Gastropods (Snails)
39. Bonneville Cutthroat Trout
40. Utah’s Giant Ice Age Birds
41. Ice Age Land Bridges and Mammal Migrations
42. Ice Age Elephants
43. Mammoth and Elephants vs. Mastodons
44. Saber-toothed Cat
45. Giant Ground Sloth
46. Other Extinct Ice Age Mammals
47. Mountain Mammals that lived in Ice Age Lowlands