In the U.S. state of Idaho, U.S. Route 95 (US-95) is a north–south highway near the western border of the state, stretching from Oregon to British Columbia for over ; it was earlier known in the state as the North and South Highway.
As indicated by its original name, it is the primary north-south highway in Idaho; US 95 connects the Boise metropolitan area in southwestern Idaho with the small cities of Fruitland, Payette, Weiser, and New Meadows within the Mountain Time Zone portion of the state. North of the Salmon River, where it enters the Pacific Time Zone, US 95 provides an important link to the cities of Grangeville (via SH 13), Lewiston (via US 12), and directly serves Moscow, Coeur d'Alene, Sandpoint, and Bonners Ferry, before reaching the Canadian border at its northern terminus and continuing into the province of British Columbia as Highway 95. It is also the only road to connect the Idaho Panhandle with the rest of the state.
Route description
US-95 continues into Idaho from southeastern Oregon as an undivided two-lane highway for the majority of its length. As it is the state's primary north–south highway, Idaho is in the process of widening US-95 to an Interstate-style divided four-lane highway, from the Oregon state line in the southwest to Eastport at the northern border with Canada at Kingsgate, British Columbia.
In Oregon, US-95 continues south, crosses into Nevada at McDermitt, and meets Interstate 80 at Winnemucca.
Oregon border to New Meadows
US-95 departs Malheur County, Oregon, and enters Idaho in the high desert of Owyhee County, about southwest of Boise. It progresses north-northeast to just west of Marsing, where it meets with the southern terminus of State Highway 55. US-95 then turns briefly west, then north to Homedale, and crosses the Snake River before a junction with concurrent US-20 and US-26 as it passes through Parma. US-95 runs north concurrent with US-20/26 for .
As it proceeds north near Idaho's western border, US-95 crosses Interstate 84 (exit 3) and US-30 before proceeding north through Payette and Weiser. It continues on to Midvale, Cambridge, and Council, then climbs into the Payette National Forest, passing the Tamarack sawmill site, and turns east to New Meadows. Here, US-95 joins with Highway 55, the two-lane undivided route that connects to Boise through McCall, Cascade, and Horseshoe Bend. The elevation at the junction in New Meadows is above sea level.
Meadows Valley to Lewiston
US-95 continues north through Meadows Valley north of the junction, then descends with the Little Salmon River to Riggins, tree-sparse but surrounded by mile-high mountains (vertical drop). Immediately after Riggins, the highway crosses the main Salmon River, crossing from the Mountain Time Zone to the Pacific Time Zone; the current tied-arch Goff Bridge was completed in 1999, replacing the truss edition of 1936; the original bridge was built in 1911 and moved to Stites in 1936.
Northbound US-95 gradually descends with the widening river, crossing it two more times (re-entering the Mountain Time Zone and leaving it within a half-mile), until White Bird, where it climbs in to the cut at the top of White Bird Hill, peaking at an elevation of with an average gradient of over 7%. The steeper, straighter, and faster multi-lane grade was opened in 1975, after ten challenging years of construction. The two-lane road of 1921 to the east was first paved in 1938; it left the Salmon River at White Bird Creek following it up through the town of White Bird, and then gradually climbed the grade in twice the distance, with multiple switchback curves. The arcs, if combined, would form 37 full 360° circles, an average of 950° per mile (590° per km). Following the completion of the new steel bridge over White Bird Creek, the new routing opened in June 1975, ending a decade of construction. The new Lewiston grade to the north was finished in just over two years.