From the website:
An independent petroleum refiner in the United States with operations throughout the mid-continent, southwestern and Rocky Mountain regions. Subsidiaries of HollyFrontier produce and market gasoline, diesel, jet fuel, asphalt, heavy products and specialty lubricant products. Additionally, HollyFrontier owns Petro-Canada Lubricants Inc. whose Mississauga, Ontario facility produces 15,600 barrels per day of base oils and other specialized lubricant products.