State Route 1, 3 and 4 in Idaho

By | October 14, 2022

State Route 1 in Idaho

Get started Copeland
End Porthill (CDN)
Length 11 mi
Length 18 km

State Route 1, also known as SH-1, is a state route in the U.S. state of Idaho. The road forms a north-south route in the far north of the state, from US 95 to the Canadian border at Porthill. SH-1 is 18 kilometers long.

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Travel directions

SH-1 branches off US 95 near the hamlet of Copeland and then heads northwest through the Kootenai River valley. To the west are mountain ranges with peaks up to 2,300 meters. At Porthill, the border with Canada follows, then Highway 21 in British Columbia continues to Creston.

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In the 1920s, SH-1 was a much longer route, running from the capital Boise via Lewiston and Coeur d’Alene to the Canadian border at Porthill. From 1926, most of it was replaced by US 95. It was envisioned that most through traffic into Canada would go a little further east towards Cranbrook, as this route better connects to the road network of the British Columbia valleys. North of Creston is not a good through route to the north because there is no fixed connection over Kootenay Lake.

Porthill-Rykerts Border Crossing

The Porthill-Rykerts Border Crossing was inaugurated in 1883, initially primarily for inspection of boats crossing the Canada-United States border via the Kootenai River. The border crossing for motorized traffic was opened in the 1930s. At the end of the 1960s, the border crossing on the American side was slightly modernized. It is one of two border crossings between Idaho and Canada.

Traffic intensities

Every day, 1,100 vehicles drive near US 95, dropping to 700 vehicles on the border with Canada.

State Route 3 in Idaho

Begin Spalding
End Rose Lake
Length 118 mi
Length 189 km







St. Maries

Rose Lake

State Route 3, also known as SH-3 is a state route in the U.S. state of Idaho. The road forms a fairly long north-south route through the north of the state, from near Spalding to Interstate 90 at Rose Lake. SH-3 is 189 kilometers long.

Travel directions

SH-3 begins near the hamlet of Spalding in the Clearwater River valley on US 12, not far east of the town of Lewiston. The road heads north through a canyon and then rises to a fairly barren plateau. The road then has few differences in height and passes through a few villages. North of Deary one enters an area with more forest and greater height differences. The road leads through sparsely populated areas, with only a few small villages on the route. One crosses several east-west side roads. The mountains in the area are up to 2,000 meters high. The largest town on the route is St. Maries, where it crosses the Saint Joe River. The road then heads well east of Coeur d’Alene Lake and ends near the hamlet of Rose Lake at a junction with Interstate 90.


The road has always had a somewhat secondary importance to the important north-south route in the region, SH-1 which was later renumbered US 95. Despite its length, the road mainly passes through small villages, only St. Maries is a slightly larger place. The road mainly opens up the countryside and connects the villages. The road is of little importance for through traffic. Parts of the route are scenic.

Traffic intensities

The road has variable but generally low road use. In the southern part, 1,500 to 3,000 vehicles a day, in the middle part about 500 to 1,000 vehicles a day and in the northern part about 1,000 to 1,500 vehicles a day. The busiest point is in St. Maries with nearly 8,000 vehicles per day.

State Route 4 in Idaho

Get started Wallace
End burke
Length 7 mi
Length 12 km

State Route 4 or SH-4 is a state route in the U.S. state of Idaho. The road provides a short connection between Wallace and the ghost town of Burke in the north of the state. State Route 4 is 12 miles long.

Travel directions

State Route 4 begins in Wallace at its junction with Interstate 90, at 850 feet above sea level. The road then leads through a narrow valley in a northeasterly direction. The surrounding mountains have peaks of up to 2,000 meters. After the ghost town of Burke, the road becomes National Forest Road No. 7623 to the Montana border.


The road was originally planned to connect Wallace, Idaho, and Thompson Falls, Montana, over the 1,761-foot Glidden Pass. Later, a route was planned over the nearby and slightly lower Cooper Pass on the border with Montana. Ultimately, the road was built no further than Burke, although the road over the Cooper Pass does exist as an unpaved forest service road.

Traffic intensities

Every day, 1,000 vehicles drive in Wallace and 500 vehicles outside it.

State Route 4 in Idaho