Larch Mountain is located in Multnomah County, Oregon approximately east of Portland, above the Columbia River Gorge. Although it has an elevation of , its prominence above the surrounding terrain is only . The summit of the mountain is accessible by Larch Mountain Road between May and November, which branches off from the Historic Columbia River Highway east of Corbett. Due to the risk of driving on the mountain's upper slopes in winter weather, the road closes during the winter months at milepost 10.