High Quality Content by WIKIPEDIA articles! In the U.S. state of Oregon, U.S. Route 101, a major north?south U.S. Highway, runs through the state along the coastline near the Pacific Ocean. In Oregon, it runs from the Oregon?California border, south of Brookings, to the Oregon?Washington border on the Columbia River, between Astoria, Oregon and Megler, Washington. U.S. 101 is known in Oregon as the Oregon Coast Highway No. 9, as it serves the Oregon Coast region. Much of the highway runs between the Pacific Ocean and the Oregon Coast Range, thus U.S. 101 is frequently mountainous in character. For most of its length it is a 2-lane undivided highway. Many parts of the highway are subject to closure due to landslides caused by excessive rainfall, and in many parts of the coast, U.S. 101 is the only viable route connecting certain coastal communities. Thus, in many cases when landslides block U.S. 101, the detour requires traveling inland to Interstate 5 and then back again.