State Route 89 (SR 89) is a state highway in the U.S. state of California that travels in the north–south direction, serving as a major thoroughfare for many mountain communities in the Sierra Nevada and the Cascade Range. It starts from U.S. Route 395 near Topaz Lake, winding its way up to the Monitor Pass, down to the Carson River, and up again over the Luther Pass. From that point on, the route generally loses elevation on its way past Lake Tahoe, through Tahoe and Plumas National Forests until Lake Almanor. For roughly nine miles the route is then a part of State Route 36. The route then ascends to the Morgan Summit. After it enters Lassen Volcanic National Park it continues to gain elevation until it reaches its highest point in an unnamed pass in the middle of Lassen Peak and Bumpass Mountain. The road then descends and heads northwest, finally terminating at Interstate 5 at the foot of Mount Shasta at around . Route description SR 89 begins at an intersection with US 395. The highway goes west through a few switchbacks before crossing into Alpine County and the Humboldt-Toiyabe National Forest. The route over Monitor Pass is typically closed during the winter due to snow accumulation. SR 89 continues by Heenan Lake before intersecting with the eastern end of SR 4 and turning northwest, passing through Markleeville. SR 89 continues northwest to the town of Woodfords, where it turns west, running concurrently with SR 88 for a brief distance before turning into El Dorado County. The section of SR 89 from SR 88 north to US 50 is co-signed as US 50 Alternate for use as a detour for when US 50 closes. The highway continues north to Meyers, where it runs concurrently with US 50 into the city of South Lake Tahoe. SR 89 continues along the western shore of Lake Tahoe, where it passes through Camp Richardson, Emerald Bay, Meeks Bay, Pomins, and Tahoma. After crossing into Placer County, SR 89 passes through Chambers Lodge, Homewood, Tahoe Pines, Skyland, Timberland, Pineland, and Tahoe Tavern before coming to an intersection with SR 28, where SR 89 continues to the west, away from the lake. The road curves to the north through Tahoe National Forest before crossing into Nevada County and the city of Truckee. This portion of the highway has been designated the "10th Mountain Division