Beverly, Washington, United States, is a small unincorporated community along the banks of the Columbia River in central Washington state. The community, which consists of a few hundred residents, is a few miles downriver from Wanapum Dam and is nestled at the base of Sentinel Gap, a water gap in the Saddle Mountains that predates the Columbia Riv…Beverly, Washington, United States, is a small unincorporated community along the banks of the Columbia River in central Washington state. The community, which consists of a few hundred residents, is a few miles downriver from Wanapum Dam and is nestled at the base of Sentinel Gap, a water gap in the Saddle Mountains that predates the Columbia River. The population as of 2020 was 266.