- Welcome to the USDA Forest Service Columbia River Gorge National Scenic Area The Columbia River Gorge is a spectacular river canyon cutting the only sea-level route through the Cascade Mountain Range. It's 80 miles long and up to 4, 000 feet deep with the north canyon walls in Washington State and the south canyon walls in Oregon State. The Columbia River Gorge is more than a gorgeous, natural ...www.fs.fed.us/r6/columbia