The Cave Rock Tunnel is a dual bore highway tunnel on U.S. Route 50 (US 50) along the eastern shore of Lake Tahoe approximately seven miles (11.4 km) north of Stateline, in Douglas County, Nevada, United States. To the Washoe Indian Tribe, Cave Rock (Washo: De ek Wadapush ) is considered a sacred place and the tribe has placed restrictions on recreational activities in the vicinity of the tunnel.DescriptionThe tunnels carry U.S. Route 50 through Cave Rock, a mountain along the eastern shore of Lake Tahoe. There are numerous small caves adjacent to the south portal of both tunnels which give the rock its name. The tunnel is located between the towns of Zephyr Cove and Glenbrook along the US 50 corridor. This portion of US 50 is a National Scenic Byway, part of the Lake Tahoe - Eastshore Drive. The westbound bore is 153ft long and features exposed rock; the eastbound bore features a concrete liner and is 410ft long. The tunnels are an elevation of at approximately 6360ft, about 80ft above the level of the lake.HistoryThe tunnel dates back to the Lincoln Highway. Originally the Lincoln Highway was routed along a single lane hanging bridge and rock wall built in 1863. Recognizing the inadequacy of the single lane road, efforts began to improve capacity on the primary road to Lake Tahoe. The first bore was constructed in 1931, as part of a reconstruction of a 3mi section of the Lincoln Highway. Concerned about damaging Cave Rock, the project managers employed key people from the recently completed Zion-Mt. Carmel Tunnel in what is now Zion National Park in Utah. The first traffic began flowing through the bore in mid-September of that year. Construction on the second bore began in 1957, when US 50 was widened to four lanes, at a cost of just over $450,000. Coincidentally, both bores were constructed by Utah-based construction companies.