On April 10, 2018, R. Kevin Hardage, a member of the Board of Directors (the “Board”) of HollyFrontier Corporation (the “Company”), notified the Board that he withdraws his name from nomination for re-election to the Board at the Company’s 2018 Annual Meeting of Stockholders (the “Annual Meeting”). Mr. Hardage will continue to serve on the Board as a director through the certification of the results of the vote at the Annual Meeting. The Board has determined that it will not nominate a replacement director for election at the Annual Meeting, and, as a result, the Board reduced the size of the Board to ten directors effective as of the certification of the results of the vote at the Annual Meeting.

About HOLLYFRONTIER CORPORATION (NYSE:HFC)

HollyFrontier Corporation (HollyFrontier) is an independent petroleum refiner. The Company produces various refined products, such as gasoline, diesel fuel, jet fuel, specialty lubricant products, and specialty and modified asphalt. The Company operates through two segments: Refining and Holly Energy Partners, L.P. (HEP). The Refining segment includes the operations of the Company’s El Dorado, Tulsa, Navajo, Cheyenne and Woods Cross Refineries and HollyFrontier Asphalt Company (HFC Asphalt). The Company’s refinery operations serve the Mid-Continent, Southwest and Rocky Mountain regions of the United States. The HEP segment involves all of the operations of HEP. HEP is a limited partnership, which owns and operates logistic assets consisting of petroleum product and crude oil pipelines, terminals, tankage, loading rack facilities and refinery processing units that principally support the Company’s refining and marketing operations.