PINNACLE ENTERTAINMENT, INC. (NASDAQ:PNK) Files An 8-K Other Events
Item 8.01 Other Events.

The first paragraph on page 106 of the Definitive Proxy Statement concerning the “Opinion of Pinnacle’s Financial Advisor” is amended and restated in its entirety by deleting the following strikethrough text and adding the following bolded and underlined text:

to an engagement letter dated December11, 2017, Pinnacle formally retained formalized its arrangements with J.P. Morgan, which had served as Pinnacle’s its financial advisor in connection with the merger since early 2017.

The following sentence is added after the first sentence of the fourth paragraph on page 108 of the Definitive Proxy Statement concerning the “Opinion of Pinnacle’s Financial Advisor – Public Trading Multiples”:

The foregoing calculations produced trading multiples of 6.9x and 7.5x for Pinnacle and Penn, respectively, based on equity research analyst estimates, and 7.0x for Pinnacle based on management projections.

The first sentence of the third paragraph on page 109 of the Definitive Proxy Statement concerning the “Opinion of Pinnacle’s Financial Advisor – Discounted Cash Flow Analysis” is amended and restated in its entirety by adding the following bolded and underlined text:

J.P. Morgan calculated the unlevered free cash flows that Pinnacle is expected to generate during fiscal years 2017 through 2021, which were based upon financial projections prepared by the management of Pinnacle and upon extrapolations reviewed and approved by the management of Pinnacle for the fiscal years 2022 through 2026 under both existing tax rates and as adjusted for a reduction in Federal tax rates to 21% under then-proposed legislation, and in each case excluding synergies.

The third sentence of the third paragraph on page 109 of the Definitive Proxy Statement concerning the “Opinion of Pinnacle’s Financial Advisor – Discounted Cash Flow Analysis” is amended and restated in its entirety by deleting the following strikethrough text and adding the following bolded and underlined text:

For purposes of the foregoing analysis, the unlevered free cash flows in the terminal year were calculated by J.P. Morgan to be $164million (assuming then-current tax rates), with a range of implied terminal exit multiples of 5.7x to 7.0x and $201million (assuming Federal tax rate of 21%), with a range of implied terminal exit multiples of 6.7x to 8.2x, in each case based on the projections provided by Pinnacle’s management.

The following sentence is added to the end of the paragraph on page 121 of the Definitive Proxy Statement concerning the “Interests of Certain Pinnacle Directors and Executive Officers in the Merger – Arrangements with Penn”:

Prior to the signing of the merger agreement, neither Pinnacle’s Chief Executive Officer nor its President and Chief Financial Officer had discussions with Penn regarding arrangements or agreements for employment following the effective time. In addition, prior to the signing of the merger agreement, none of Pinnacle’s directors had discussions with Penn regarding possible directorships with the combined company.

—END OF SUPPLEMENT TO DEFINITIVE PROXY STATEMENT—

Pending Penn Shareholder Litigation.

On March6, 2018, Penn received a letter dated March5, 2018 on behalf of purported Penn shareholder Robert Garfield (“Garfield”) demanding that Penn file suit against the members of the board of directors of Penn (the “Penn board”).The letter alleged, among other things, that the board members breached fiduciary duties in connection with the entry into the Merger Agreement, and through causing Penn to make allegedly materially inadequate disclosures and material omissions in the Definitive Proxy Statement.On March9, 2018, Garfield filed a putative derivative and purported class action lawsuit captioned Garfield v. Carlino, No.18-2652, in the Court of Common Pleas of Berks County, Pennsylvania against members of the Penn board, with Penn as a nominal defendant, alleging several claims under Pennsylvania law based on substantially the same allegations raised in his letter. On March13, 2018, the Penn board appointed an independent special litigation committee to review, investigate, and evaluate the claims on behalf of Penn.On March16, 2018, Garfield filed a motion for a preliminary injunction and expedited discovery. The defendants believe that the action is without merit.

Important Additional Information

In connection with the proposed transaction, on February8, 2018, Penn filed with the Securities and Exchange Commission (the “SEC”) a registration statement on Form S-4 that contains a joint proxy statement of Penn and Pinnacle and also constitutes a prospectus of Penn (the “joint proxy statement/prospectus”). The registration statement was declared effective by the SEC on February28, 2018 and Penn and Pinnacle commenced mailing the definitive joint proxy statement/prospectus to their respective shareholders and stockholders on February28, 2018. This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. SHAREHOLDERS OF PENN AND STOCKHOLDERS OF PINNACLE ARE URGED TO READ THE DEFINITIVE JOINT PROXY STATEMENT/PROSPECTUS REGARDING THE PROPOSED TRANSACTION AND ANY OTHER RELEVANT DOCUMENTS FILED OR THAT WILL BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THOSE DOCUMENTS, BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION. Investors may obtain a free copy of the registration statement and the joint proxy statement/prospectus, as well as other filings containing information about Penn and Pinnacle, without charge, at the SEC’s website at www.sec.gov. Copies of the documents filed with the SEC by Penn can be obtained, without charge, by directing a request to Justin Sebastiano, Penn National Gaming, Inc., 825 Berkshire Boulevard, Suite 200, Wyomissing, Pennsylvania 19610, Tel. No. (610) 401-2029. Copies of the documents filed with the SEC by Pinnacle can be obtained, without charge, by directing a request to Vincent Zahn, Pinnacle Entertainment, Inc., 3980 Howard Hughes Parkway, Las Vegas, Nevada 89169, Tel. No. (702) 541-7777.

Participants in the Solicitation

Penn, Pinnacle, and certain of their respective directors, executive officers and employees may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information regarding Penn’s directors and executive officers is available in Penn’s Annual Report on Form 10-K for the year ended December31, 2017, which was filed with the SEC on March1, 2018, and its proxy statement for its 2017 Annual Meeting of Shareholders, which was filed with the SEC on April25, 2017. Information regarding Pinnacle’s directors and executive officers is available in Pinnacle’s Annual Report on Form 10-K for the year ended December31, 2017, which was filed with the SEC on March1, 2018, and its proxy statement for its 2017 Annual Meeting of Stockholders, which was filed with the SEC on March14, 2017. Other information regarding the participants in the proxy solicitation and a description of their direct and indirect interests, by security holdings or otherwise, is contained in the definitive joint proxy statement/prospectus of Penn and Pinnacle and other relevant materials filed with the SEC. Free copies of this document may be obtained as described in the preceding paragraph.

Forward-Looking Statements

This communication may contain certain forward-looking statements, including certain plans, expectations, goals, projections, and statements about the benefits of the proposed transaction, Penn’s and Pinnacle’s plans, objectives, expectations and intentions, the expected timing of completion of the transaction, and other statements that are not historical facts. Such statements are subject to numerous assumptions, risks, and uncertainties. Statements that do not describe historical or current facts, including statements about beliefs and expectations, are forward-looking statements. Forward-looking statements may be identified by words such as “expect,” “anticipate,” “believe,” “intend,” “estimate,” “plan,” “target,” “goal,” or similar expressions, or future or conditional verbs such as “will,” “may,” “might,” “should,” “would,” “could,” or similar variations. The forward-looking statements are intended to be subject to the safe harbor provided by Section27A of the Securities Act of 1933, Section21E of the Securities Exchange Act of 1934, and the Private Securities Litigation Reform Act of 1995.

While there is no assurance that any list of risks and uncertainties or risk factors is complete, below are certain factors which could cause actual results to differ materially from those contained or implied in the forward-looking statements including: risks related to the acquisition of Pinnacle by Penn and the integration of the businesses and assets to be acquired; the possibility that the proposed transaction does not close when expected or at all because required regulatory, shareholder or other approvals are not received or other conditions to the closing are not satisfied on a timely basis or at all; the risk that the financing required to fund the transaction is not obtained on the terms anticipated

or at all; the possibility that the Boyd Gaming Corporation and/or Gaming and Leisure Properties, Inc. transactions do not close in a timely fashion or at all; potential adverse reactions or changes to business or employee relationships, including those resulting from the announcement or completion of the transaction; potential litigation challenging the transaction; the possibility that the anticipated benefits of the transaction are not realized when expected or at all, including as a result of the impact of, or issues arising from, the integration of the two companies; the possibility that the anticipated divestitures are not completed in the anticipated timeframe or at all; the possibility that additional divestitures may be required; the possibility that the transaction may be more expensive to complete than anticipated, including as a result of unexpected factors or events; diversion of management’s attention from ongoing business operations and opportunities; litigation relating to the transaction; risks associated with increased leverage from the transaction; and other factors discussed in the sections entitled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Penn’s and Pinnacle’s respective most recent Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K as filed with the SEC. Other unknown or unpredictable factors may also cause actual results to differ materially from those projected by the forward-looking statements. Most of these factors are difficult to anticipate and are generally beyond the control of Penn and Pinnacle. Pinnacle does not undertake any obligation to release publicly any revisions to any forward-looking statements, to report events or to report the occurrence of unanticipated events unless required to do so by law.

About PINNACLE ENTERTAINMENT, INC. (NASDAQ:PNK)

Pinnacle Entertainment, Inc. is an owner, operator and developer of casinos and related hospitality and entertainment businesses. The Company operates through three segments: Midwest, South and West. The Company’s Midwest segment includes Ameristar Council Bluffs, Ameristar East Chicago, Ameristar Kansas City, Ameristar St. Charles, Belterra, Belterra Park, Meadows and River City. The Company’s South segment includes Ameristar Vicksburg, Boomtown Bossier City, Boomtown New Orleans, L’Auberge Baton Rouge and L’Auberge Lake Charles. The Company’s West segment includes Ameristar Black Hawk and Cactus Petes and Horseshu. As of September 30, 2016, the Company owned and operated 16 gaming entertainment businesses, located in Colorado, Indiana, Iowa, Louisiana, Mississippi, Missouri, Nevada, Ohio and Pennsylvania. The Company’s gaming entertainment businesses include gaming, food and beverage, and retail facilities, which include hotel and resort amenities.