Idaho State Highway 1
| North and South Highway Copeland – Porthill Branch Copeland – Porthill Road | ||||
ID 1 highlighted in red | ||||
| Route information | ||||
| Maintained by ITD | ||||
| Length | 11.185 mi (18.001 km) | |||
| Existed | c. 1926–present | |||
| Tourist routes | Part of the International Selkirk Loop | |||
| Major junctions | ||||
| South end | US 95 near Copeland | |||
| North end | Highway 21 in Porthill | |||
| Location | ||||
| Country | United States | |||
| State | Idaho | |||
| Counties | Boundary | |||
| Highway system | ||||
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State Highway 1 (SH-1) is a state highway in Boundary County, in the U.S. state of Idaho. It extends 11.185 miles (18.00 km) from U.S. Route 95 (US-95) east of Copeland, north to British Columbia Highway 21 (BC 21) in Porthill. The route serves as a connector between Bonners Ferry, via US-95 south, Porthill, and Creston, BC. The highway is one of two border crossings from Idaho into British Columbia. The other crossing is at the US-95/BC 95 in Eastport. The highway is also known for being the only state highway in Boundary County, the two other highways are US-95 and US-2. The highway is also part of the International Selkirk Loop, the only international scenic byway in North America.