Holly Corporation, through its subsidiaries, operates as a petroleum refiner in the United States. It involves in the purchase and refining of crude oil; and wholesale and marketing of refined products, such as gasoline, diesel fuel, and jet fuel in Texas, New Mexico, Arizona, Utah, Wyoming, Montana, Idaho, Washington, and northern Mexico. The company also manufactures and markets asphalt products from various terminals in Arizona and New Mexico. In addition, it transports liquid petroleum gas ( ...

MDU Resources Group, Inc. operates as a natural resource company in the United States. It has six segments: Electric, Natural Gas Distribution (NGD), Construction Services, Pipeline and Energy Services (PES), Natural Gas and Oil Production (NGOP), and Construction Materials and Mining (CMM). The Electric segment generates, transmits, and distributes electricity in Montana, North Dakota, South Dakota, and Wyoming. The NGD segment distributes natural gas in western Minnesota and southeastern North ...