The federal Bureau of Land Management on Wednesday “temporarily” closed 160 acres of land in the Yuba Goldfields to off-road recreational vehicles, citing damage to salmon and steelhead trout spawning grounds in the Yuba River.

The vehicles, apparently Quad Runners and possibly pickups, have been entering shallow, gravel-bottomed waters on the north and south sides of the river where fish spawn, said BLM Community Planner John Scull.

Scull said he expects the acreage will be closed at least six months during spawning season and possibly permanently.

“The BLM is mandated by law and regulations to protect critical habitat for species listed in the Federal Endangered Species Act,” said Bill Haigh, the BLM’s Folsom field office manager.

“Spring run” salmon already are classified as a threatened species, while “fall run” salmon are candidates for the designation, said BLM Wildlife Biologist Peggy Cranston.

Closure signs have been posted along Hammonton Road on the south side of the river and in the Sycamore Ranch area on the north side - both entry points for off-road vehicles, said Cranston.

Fish spawn in the Goldfields because the Daguerre Point and Engelbright dams prevent them from traveling farther upstream.

Cranston said recreational vehicle riders have found a way to get over a high gravel wall on the south side of the river, destroying fish habitat and eggs that have been laid, she said.

“This is the first year it’s come to my attention,” Cranston said.

The 9,000-acre Goldfields, eight miles east of Marysville on the Yuba River, are composed of gravel washed down the Yuba River from hydraulic mining in Nevada County durin the late 1800s. The land was then dredged to recover gold from the gravel, leaving large, steep piles of rocks.

About 472 acres of BLM-administered public land is legally accessible from Hammonton Road.