VANTAGE The state Department of Fish and Wildlife has closed five water access sites along the Columbia River behind Wanapum Dam.
The reservoir behind the dam has been down in response to a cracked spillway.
"For their own safety, we're asking people to please stay off the beaches and any other areas that were under water before the drawdown," Fish and Wildlife Regional Director Jim Brown said.
Officials said they closed the sites and are preventing access to the beach and exposed riverbed in state-managed wildlife areas along the river to protect public safety, fish habitat and archeological resources.
The reservoir behind the dam was lowered about 26 feet after divers discovered a 65-foot-long crack Feb. 27 along one of the dam's spillways.
As a result, the water level behind the dam is at its lowest point since the Grant County Public Utility District facility began operating in 1964.
Brown said the reservoir level is so low that boaters can't reach the water with their trailers, and some newly uncovered areas near the shoreline present quicksand-like conditions.
The closures affect the Yo Yo, Old Vantage Highway, Sunland Estates, Buckshot and Frenchman Coulee/Climbing Rocks access sites.
Officials also closed the lower ends of roads that lead into the reservoir at the Colockum and L.T. Murray wildlife areas in Kittitas and Chelan counties, and at the Columbia Basin Wildlife Area in Grant County.
The upland portions of the wildlife areas above the ordinary high-water level remain open to the public, Brown said.
Brown said the closures are in effect until further notice.