HFC HollyFrontier Corporation

EXPLANATORY NOTE

DEREGISTRATION OF SECURITIES

HollyFrontier Corporation, a Delaware corporation (“HollyFrontier” or the “Company”) is filing these post-effective amendments (these “Post-Effective Amendments”) to the following Registration Statements on Form S-8 (the “Registration Statements”), which were filed by the Company with the Securities and Exchange Commission (the “SEC”) on the dates set forth below, to deregister any and all shares of the Company’s common stock, par value $0.01 per share (“Common Stock”), registered but unissued under each such Registration Statement as of the date hereof:

On March 14, 2022 (the “Closing Date”), pursuant to that certain Business Combination Agreement, dated as of August 2, 2021 (as amended on March 14, 2022, the “Agreement”), by and among HollyFrontier, HF Sinclair Corporation (“HF Sinclair”), Hippo Merger Sub, Inc., a wholly-owned subsidiary of HF Sinclair (“Parent Merger Sub”), The Sinclair Companies (“Sinclair HoldCo”), and Hippo Holding LLC, a wholly-owned subsidiary of Sinclair HoldCo (the “Target Company”), HF Sinclair completed its previously announced acquisition of the Target Company by effecting (a) a holding company merger in accordance with Section 251(g) of the Delaware General Corporation Law whereby HollyFrontier merged with and into Parent Merger Sub, with HollyFrontier surviving such merger as a direct wholly-owned subsidiary of HF Sinclair (the “HFC Merger”) and (b) immediately following the HFC Merger, a contribution whereby Sinclair HoldCo contributed all of the equity interests of the Target Company to HF Sinclair in exchange for shares of HF Sinclair, resulting in the Target Company becoming a direct wholly-owned subsidiary of HF Sinclair. Effective as of the HFC Merger, each share of Common Stock issued and outstanding immediately prior to the Effective Time (as defined in the Agreement) (other than treasury shares which were cancelled pursuant to the Agreement) was automatically converted into one validly issued, fully paid and nonassessable share of common stock, par value $0.01 per share, of HF Sinclair.

As a result of the completion of the HFC Merger, HollyFrontier has terminated all offerings of shares of Common Stock pursuant to the Registration Statements. In accordance with the undertakings made by HollyFrontier in the Registration Statements to remove from registration, by means of a post-effective amendment, any of the securities that had been registered for issuance that remain unsold at the termination of such offerings, HollyFrontier hereby removes from registration by means of these Post-Effective Amendments all shares of Common Stock registered but unsold under the Registration Statements as of the date hereof. The Registration Statements are hereby amended, as appropriate, to reflect the deregistration of such shares of Common Stock and HollyFrontier hereby terminates the effectiveness of the Registration Statements.