FARMINGTON — An oil well in the Aneth oil field east of Montezuma Creek, Utah, leaked a small amount of oil into the San Juan River on Wednesday evening.

The leak occurred after a rainstorm prompted boulders to fall from a nearby hillside and strike the flow line of an oil well, causing it to crack, said Pat Flynn, vice president of corporate affairs for Resolute Energy Company, which owns the well. A flow line is a steal pipe that transports the oil from the well into the processing equipment or the storage tank.

About 165 gallons of oil flowed into a water-filled wash, which transported it to the San Juan River, Flynn said.

He said because the river was far away, less than 1 gallon of oil actually entered the river.

"It was enough to form a sheen on the river bank," Flynn said.

Absorbent booms were set out on the river to catch the oil.

Flynn said Resolute Energy Company has not detected oil downstream from the initial entry point.