The end of the Oregon Trail in The Dalles
For many emigrants, The Dalles was where the wagon road ran out and the river began. This page gives the history from the National Park Service and Wikipedia.
Where the wagons met the river
Wikipedia says the Oregon Trail ended at The Dalles for travelers on the overland route, and that before the Barlow Road opened in 1846, settlers had to raft down the Columbia to reach Fort Vancouver and the Willamette Valley. The National Park Service tells the same story: until 1846, when an overland alternative was developed, everyone had to float the river from The Dalles to Fort Vancouver. After that, many emigrants chose the Barlow Road, which let them avoid the Columbia. The Park Service notes that the trail to The Dalles forked about six miles east of town, where many turned south toward the Barlow Road.
A supply stop
The Park Service says Wascopam Mission at The Dalles, established in 1838, became an important supply stop for overlanders starting in 1841, and that parties taking the Barlow Road often resupplied there. Steamships arrived in 1851, bringing travelers headed upstream to the Idaho gold fields.
Fort Dalles and the town
The U.S. Army established Fort Dalles at the old mission site in 1850, and the military closed it in 1867. Wikipedia says the post became the nucleus of the town. The city was incorporated in 1857 and took the name The Dalles in 1860.
Learn more
The National Park Service's Oregon National Historic Trail pages carry the wider story of the trail, which it describes as more than 2,000 miles of ruts and traces that can still be seen. The Columbia Gorge Discovery Center and Museum in The Dalles keeps an Oregon Trail collection.