(2012); more than any other U.S. state. Agriculture and mining Texas has the most farms and the highest acreage in the United States. The state is ranked for revenue generated from total livestock and livestock products. It is ranked for total agricultural revenue, behind California. At $7.4 billion or 56.7 percent of Texas's annual agricultural cash receipts, beef cattle production represents the largest single segment of Texas agriculture. This is followed by cotton at $1.9 billion (14.6 percent), greenhouse/nursery at $1.5 billion (11.4 percent), broiler chickens at $1.3 billion (10 percent), and dairy products at $947 million (7.3 percent). Texas leads the nation in the production of cattle, horses, sheep, goats, wool, mohair and hay. The state also leads the nation in production of cotton which is the number one crop grown in the state in terms of value. The state grows significant amounts of cereal crops and produce. Texas has a large commercial fishing industry. With mineral resources, Texas leads in creating cement, crushed stone, lime, salt, sand and gravel. Texas throughout the 21st century has been hammered by drought. This has cost the state billions of dollars in livestock and crops. Energy Ever since the discovery of oil at Spindletop, energy has been a dominant force politically and economically within the state. If Texas were its own country it would be the sixth largest oil producer in the world according to a 2014 study. The Railroad Commission of Texas, contrary to its name, regulates the state's oil and gas industry, gas utilities, pipeline safety, safety in the liquefied petroleum gas industry, and surface coal and uranium mining. Until the 1970s, the commission controlled the price of petroleum because of its ability to regulate Texas's oil reserves. The founders of the Organization of Petroleum Exporting Countries (OPEC) used the Texas agency as one of their models for petroleum price control. As of January 1, 2021, Texas has proved recoverable petroleum reserves of about of crude oil (44% of the known U.S. reserves) and of natural gas liquids. The state's refineries can process of oil a day. The Port Arthur Refinery in Southeast Texas is the largest refinery in the U.S. Texas is also a leader in natural gas production at per day, some 32% of the nation's production. Texas has of gas reserves which is 23% of the nation's gas reserves. Many petroleum companies are based in Texas such