GORMAN-- -- A landslide is being blamed for rupturing an oil pipeline near Gorman, that sent 126,000 gallons of crude oil down a hillside and into Pyramid Lake.

L.A. County officials said light crude oil from the San Joaquin Valley flowed under Interstate 5 and down a ravine into a finger-like cove of the lake.

The U.S. Forest Service and Department of Fish and Game worked with the pipeline owner, Pacific Energy Partners, to cordon off the spill and were not concerned about contamination.

The reservoir serves as a source of drinking water for Southern California cities.

"The good news is they don't feel it's going to impact the drinking water," said Mark Reese with Pacific Energy Partners. "Right now, it's just an environmental impact but they're going to watch it very closely."

Pyramid Lake will be closed to the public until the spill can be cleaned up.

Officials have no idea at this point, just how long that will be.