"Oil and gas companies have reported almost 1,000 spills to Colorado regulators over the past 2-1/2 years, totaling 5.2 million gallons of drilling liquids and oil.

They ranged from small oil leaks from half-closed valves to thousands of barrels of tainted water that escaped from pits.

It's far from the volume of oil now shooting into the Gulf of Mexico, but a Denver Post analysis of state spill reports shows that even far from offshore, drilling for oil can regularly create unintended messes:"

Burt Hubbard reports for the Denver Post June 28, 2010. [2]