1. December 2014 Investor Update

2. ® Safe Harbor 2 Some of the matters discussed in this presentation may contain forward-looking statements that are subject to certain risks, uncertainties and assumptions. Such forward-looking statements are intended to be identified in this document by the words "anticipate", "believe", "estimate", "expect", "intend", "objective", "plan", "possible", "potential", "project" and similar expressions. Actual results may vary materially. Factors that could cause actual results to differ materially include, but are not limited to: general economic conditions, including the availability of credit, access to existing lines of credit, access to the commercial paper markets, actions of rating agencies and their impact on capital expenditures; the ability of the Company and its subsidiaries to access the capital markets and obtain financing on favorable terms as well as inflation rates and monetary fluctuations; prices and availability of electricity, coal, natural gas and natural gas liquids; the timing and extent of changes in commodity prices, particularly natural gas and natural gas liquids, the competitive effects of the available pipeline capacity in the regions Enable Midstream Partners serves, and the effects of geographic and seasonal commodity price differentials, including the effects of these circumstances on re-contracting available capacity on Enable Midstream Partners' interstate pipelines; the timing and extent of changes in the supply of natural gas, particularly supplies available for gathering by Enable Midstream Partners' gathering and processing business and transporting by Enable Midstream Partners' interstate pipelines, including the impact of natural gas and natural gas liquids prices on the level of drilling and production activities in the regions Enable Midstream Partners serves; business conditions in the energy and natural gas midstream industries including the demand for natural gas, natural gas liquids, crude oil and midstream services; competitive factors including the extent and timing of the entry of additional competition in the markets served by the Company; unusual weather; availability and prices of raw materials for current and future construction projects; Federal or state legislation and regulatory decisions and initiatives that affect cost and investment recovery, have an impact on rate structures or affect the speed and degree to which competition enters the Company's markets; environmental laws and regulations that may impact the Company's operations; changes in accounting standards, rules or guidelines; the discontinuance of accounting principles for certain types of rate-regulated activities; the cost of protecting assets against, or damage due to, terrorism or cyber attacks and other catastrophic events; advances in technology; creditworthiness of suppliers, customers and other contractual parties; difficulty in making accurate assumptions and projections regarding future revenues and costs associated with the Company's equity investment in Enable Midstream Partners that the Company does not control; the risk that Enable Midstream Partners may not be able to successfully integrate the operations of Enogex LLC and the businesses contributed by a wholly-owned subsidiary of CenterPoint Energy, Inc.; and other risk factors listed in the reports filed by the Company with the Securities and Exchange Commission including those listed in Risk Factors and Exhibit 99.01 to the Company's Form 10-K for the year ended December 31, 2013.

3. OGE has a clear, conservative and achievable set of financial objectives centered around investment grade credit ratings, long- term EPS growth and conservative, yet steady, dividend growth 3 3 OGE Energy Corp (NYSE: OGE) Well positioned regulated utility with growing service territory Over $1.5 billion of transmission projects completed by the end of 2014 Over $1 billion of environmental compliance projects to be completed by January 2019 Economic conditions in Oklahoma have been more favorable compared to the rest of the U.S. OGE holds a 26.3% limited partner interest and a 50% general partner interest of Enable Midstream Partners, LP Enhanced scale, with approximately $11 billion of combined assets Significant asset positions in a broad range of basins, including the Granite Wash, Tonkawa, Mississippi Lime, Cana Woodford, Haynesville, Fayetteville, Barnett and Woodford plays

4. 4 OG&E Facts Regulated electric utility: 813,000 customers Generating capacity: 6,785 megawatts, 7 power plants, 3 wind farms Service territory: 30,000 square miles in Oklahoma and western Arkansas 2,360 Full-time (non-union) Employees 2013 EEI Edison Award for the implementation of its Smart hours Program Electric Power and Light’s 2011 Utility of the Year J.D. Power and Associates’ 2012 & 2013 Electric Utility Residential Customer Satisfaction Study

5. 5 Oklahoma City is the country’s 12 th fastest growing city in 2013 … Confidential

6. Oklahoma’s economy continues to outperform the nation… Oklahoma Treasury 12 Month Gross Receipts 2 Unemployment: Oklahoma vs. U.S. 1 Oklahoma’s unemployment rate remains lower than the US unemployment rate 1 Tax collections have reach an all-time high as of September 2014 2 1 As of October 2014, BLS 2 Office of the Oklahoma State Treasurer 6 Confidential

7. 7 OG&E 2013 MWH ENERGY 2013 NAMEPLATE CAPACITY Confidential 2013 MWH SALES MIX 2013 REVENUE MIX Generation and Capacity by Fuel Type Sales and Revenue by Customer Class

8. Focus for Execute on the $100 million of transmission spend in 2014 Execute compliance strategy for environmental regulations specifically, Regional Haze and MATS Continue to develop energy management solutions for OG&E’s customers through the Smart Grid program Manage spending versus reliability and balance investments for the ultimate benefit of customers Seek additional transmission opportunities within the SPP via FERC Order 1000 8

9. Environmental challenges and deadlines Regional Haze – Legal measures have been exhausted so OG&E now must comply with the Environmental Protection Agency (EPA) Federal Implementation Plan (FIP) by January 4, 2019 Mercury Air Toxics Rules (MATS) - OG&E requested and has received a one-year extension for compliance to April 16, 2016 from the Oklahoma Department of Environmental Quality EPA accepts BART determination for NOx but reject SO 2 determination Oklahoma SIP Submitted OG&E Appeals to 10 th Circuit of Appeals upholds EPA’s rejection OG&E requests rehearing by full panel of judges Rehearing request denied OG&E appeals to U.S. Supreme Court declines to hear Regional Haze Case 20102011 2012 2013 2014 9

10. MATS Extension Date Project Completion Schedule MATS Compliance Date Q2Q3Q4 Q2 Q3 Q4 Q2 Q3Q4Q2Q3Q4Q2Q3 20172018 2015 20162019 Q4 2014 Low NOX Burners ACI Scrub Sooner Unit Convert Muskogee Mustang CTs Regional Haze compliance date is set 55 months from US Supreme Court decision. Clock restarted 5/29/2014 + 55 months = 1/4/2019. Scrub Sooner Unit Regional Haze Compliance Date 10

11. Environmental Compliance Plan Update 11 Activated Carbon Injection Install on 5 coal units by 2016 Finalize installation contracts in Q1 2015 and construction will begin in the second half of 2015 Low NOX burners Install on 7 units by 2017 Installation is complete on 3 units and we are in the permitting process for the remaining burners Scrubbers Add dry scrubbers to 2 coal units by 2018 An equipment vendor for the 2 dry scrubbers has been selected and the selection of the installation vendor is expected in Q1 of 2015 Natural Gas conversion Convert 2 coal units to gas by 2019 Engineering studies for the conversion of 2 gas plants at Muskogee are ongoing and expected to be complete by mid-2015 with permit applications submitted to the Oklahoma Department of Environmental Quality in the second half of 2017 Mustang Modernization Replace the Mustang plant with 400 MWs of combustion turbines by 2018 Bids for the Mustang plant turbines are expected by Q1 2015

12. Procedural Schedule 12 DateAction Monday, October 31, 2014Deadline for filing Motions to Intervene Tuesday, November 25, 2014Discovery Cut-Off for Direct Testimony Tuesday, December 16, 2014Responsive Testimony Filed Monday, December 22, 2014Statements of Position Filed from all parties not filing Responsive Testimony Thursday, January 15, 2015Discovery Cut-Off for All Responsive Testimony Monday, January 26, 2015Rebuttal Testimony Filed by All Parties Friday, January 30, 2015Settlement Conference 10:00am, Courtroom 301 Friday, February 6, 2015Discovery Cut-Off for all Rebuttal Testimony Friday, February 13, 2015All Pre-Trial Motions to be Filed Friday, February 13, 2015Objections to Witness Qualifications Filed Tuesday, February 17, 2015Settlement Conference, 10:00am, Courtroom 301 Friday, February 20, 2015Exhibit Lists Filed and Exchanged; Testimony Summaries Filed Tuesday, February 24, 2015Pre-Hearing Conference; all pre-trial motions heard 10:00am Tuesday, March 3, 2015Hearing on the Merits, 10:00am, Courtroom 301 Due 14 business days following the close of the Hearing on the Merits Proposed Findings of Fact and Conclusions of Law Filed

13. OG&E is gradually shifting generation resources while maintaining fuel diversity 13

14. 14 Projected Environmental Expenditures 2014 - 2018 * Planned environmental expenditures in 2019 are $35 million and $55 million for combustion turbines and scrubbers, respectively.

15. 15 Projected Rate Base 2014 - 2018

16. Regulatory Overview Oklahoma Corporation Commission 3 elected commissioners serve with 6 year terms Commissioner Douglass has announced that she will run for a congressional seat in the November 2014 election The vacated commissioner position will be filled in the November 2014 general election Arkansas Public Service Commission 3 appointed commissioners serve with 6 year terms FERC Transmission OG&E has a formula rate with 11.1% ROE and up to 56% equity 16

17. Consistent dividend growth *Quarterly dividend rate declared by the Board of Directors in September 2014 17 5% 6%8%11% 5 year dividend growth rate of 10% per year through 2019

18. 18 Solid credit ratings with stable outlook Moody’sS&PFitchOutlook OG&EA1A-A+Stable OGE Energy Corp.A3BBB+A-Stable

19. Summary Environmental Compliance Funded by Enable distributions, utility cash flow and debt Strong credit ratings and capital structure will be maintained Oklahoma approval expected in the first quarter of 2015 SPP project selection scheduled for the first quarter 2015 The economy in the service territory remains strong as OG&E continues to see new customer growth above 1% OGE increased the fourth quarter 2014 dividend 11% and announced plans to growth the dividend 10% per year through 2019 The utility and Enable Midstream growth rates will be refreshed on the fourth quarter 2014 earnings call 19

20. Appendix

21. ® Third Quarter EPS Results 21 3Q 20143Q 2013YTD 2014YTD 2013 OG&E$.79$0.86$1.28$1.32 OGE Holdings (Natural Gas Midstream Operations) 0.14 0.23 0.41 0.37 Hold. Co.0.01(0.01)-(0.03) Consolidated$0.94$1.08$1.69$1.66

22. Third Quarter Results – OG&E In Millions of $3Q 20143Q 2013 Variance Fav/(Unfav) Gross Margin 449.4450.2(0.8) Operation & Maintenance 111.0105.9(5.1) Depreciation & Amortization 69.462.5(6.9) Interest Expense 35.331.6(3.7) Net income for OG&E was $157.4 million or $0.79 per share in 2014 as compared to net income of $171.5 million or $0.86 per share in 2013. Primary drivers include: 22

23. Third Quarter Results - OG&E Gross Margin 23 Millions of $ Gross Margin Drivers: Transmission Revenues Growth Weather

24. Third Quarter Results – Natural Gas Midstream Operations Net income to OGE was $28 million or $.14 per share in 2014 as compared to net income of $46 million or $.23 per share in 2013. 24

25. Reg. G Reconciliation of Gross Margin to Revenue 25 Three Months Ended Sep 30, (In millions) 2014 2013 Operating revenues$754.7 $723.2 Cost of sales 305.3 273.0 Gross Margin$449.4 $450.2 Gross Margin is defined by OG&E as operating revenues less fuel, purchased power and certain transmission expenses. Gross margin is a non-GAAP financial measure because it excludes depreciation and amortization, and other operation and maintenance expenses. Expenses for fuel, purchased power and transmission expenses are recovered through fuel adjustment clauses and as a result changes in these expenses are offset in operating revenues with no impact on net income. OG&E believes gross margin provides a more meaningful basis for evaluating its operations across periods than operating revenues because gross margin excludes the revenue effect of fluctuations in these expenses. Gross margin is used internally to measure performance against budget and in reports for management and the Board of Directors. OG&E's definition of gross margin may be different from similar terms used by other companies.

26. Projected Capital Expenditures 2014 – 2018 26