sentences:  It has a surface area of 6,590 acres (27 km²), a maximum storage capacity of , normally kept at .As the reservoir filled in 1968, it flooded several archaeological sites, including the Marmes Rockshelter, which contained the oldest known artifacts in Washington, dating back over 10,000 years.The lake was named for Herbert G. West, a major promoter of inland navigation on the Columbia and Snake rivers.