LUDLOW ---- BrightSource Energy Inc. said on Thursday it has dropped plans to build a solar thermal power facility in the eastern Mojave Desert where a U.S. senator wants to turn the land into a national monument.

The move was welcomed by environmentalists, who opposed the solar development on part of the Broadwell Dry Lake in San Bernardino County that is home to unique plants and animals.

Earlier this year, Sen. Dianne Feinstein, D-Calif., said she wants to preserve 500,000 desert acres from solar or wind facilities.

"We have ceased all activity at the Broadwell site. We will not build inside of a national monument," BrightSource spokesman Keely Wachs told the Los Angeles Times.

Environmentalists were concerned the 500-megawatt facility would encroach on the big horn mountain sheep and other wildlife that even led to a public dispute with Robert Kennedy Jr., a senior advisor at VantagePoint Venture Partners, which has a multimillion-dollar stake in BrightSource, according to David Myers, executive director of the Wildlands Conservancy.

Brightsource has other applications for solar projects pending with the U.S. Bureau of Land Management.