Sylvan Goldman of Oklahoma created the first rolling supermarket cart. The first parking meter was created in Oklahoma and installed in Oklahoma City in 1935. Oklahoma has 43 colleges and universities. Oklahoma is the winter quarters for more circuses than any other state. Oklahoma's average annual temperature is a pleasant 60.5 degrees.
Tourism is one of Oklahoma's top three industries in terms of economic impact on the state.
Last year travelers to Oklahoma spent over 3 billion dollars. The Poteau River is the only river in Oklahoma that flows north. The world's largest single deposit of pure alabaster may be found in the Alabaster caverns near Freedom, Oklahoma. Oklahoma has the distinction of having the highest hill in the world, Mount Cavanal, at 1,999 feet. The largest lake in Oklahoma is Lake Eufaula, covering 102,000 surface acres of water.