Although there are a few hotels in The Dalles, you should stay in Hood River, which is only 20 miles away and has a better selection of accommodations plus lots of great restaurants.
Campgrounds -- If you want to pitch a tent or park an RV, try Deschutes River State Recreation Area, 17 miles east of The Dalles off I-84. For reservations, contact ReserveAmerica (tel. 800/452-5687; www.reserveamerica.com). On the Washington side of the Gorge, there is camping at Columbia Hills State Park (no reservations), near the community of Dallesport (take U.S. 197 north to Wash. 14 east).