Wascopam Mission, or the Dalles Mission, was a Methodist outpost founded in 1838 at Celilo Falls in present-day The Dalles, Oregon, as part of the wider Oregon Country mission effort. Built with help from neighboring Wasco people, it served several Indigenous communities and included a schoolhouse, farm buildings, dwellings, and pasture. Supplies arrived from regional forts and mission stations. Its most visible surviving feature is Pulpit Rock, where outdoor services were held. After the mission closed in 1847, the site passed through Whitman, militia, federal, and military hands, becoming Fort Dalles and later part of the town, while legal disputes over the property continued into the 1880s.