NuStar Energy L.P. engages in the terminalling, storage, and transportation of petroleum products primarily in the United States and the Netherlands. The company operates in three segments: Storage, Transportation, and Asphalt and Fuels Marketing. The Storage segment owns terminal and storage facilities for petroleum products, specialty chemicals, crude oil, and other feedstocks; and crude oil storage tanks. Its terminals also offer pilotage, tug assistance, line handling, launch, emergency response, and other ship services. The Transportation segment transports refined petroleum products, crude oil, and anhydrous ammonia. It operates refined product pipelines in Texas, Oklahoma, Colorado, New Mexico, Kansas, Nebraska, Iowa, South Dakota, North Dakota, and Minnesota. The Asphalt and Fuels Marketing segment refines crude oil to produce asphalt and other refined products. This segment also purchases crude oil and other refined petroleum products for resale. As of December 31, 2012, the company had 61 terminal and storage facilities providing approximately 83.2 million barrels of storage capacity; 5,484 miles of refined product pipelines with 21 associated terminals that offer storage capacity of 4.9 million barrels, as well as 2 tank farms providing storage capacity of 1.4 million barrels; 2,000 miles of anhydrous ammonia pipelines; 1,150 miles of crude oil pipelines with 2.5 million barrels of associated storage capacity; a fuels refinery with a throughput capacity of 14,500 barrels per day and 0.4 million barrels of aggregate storage capacity; and a 50% ownership interest in a joint venture that owned a terminal and an asphalt refinery with a throughput capacity of 74,000 barrels per day with a combined storage capacity of 5.3 million barrels. Riverwalk Logistics, L.P. serves as the general partner of the company. The company was founded in 1999 and is headquartered in San Antonio, Texas.