| State: | ID |
| Type: | ID |
| Route: | 1 |
| Alternate Name: | North and South Highway Copeland – Porthill Branch Copeland – Porthill Road |
| Maint: | ITD |
| Map Custom: | yes |
| Map Notes: | ID 1 highlighted in red |
| Length Mi: | 11.185 |
| Length Round: | 3 |
| Length Ref: | [1] |
| Direction A: | South |
| Terminus A: | near Copeland |
| Direction B: | North |
| Terminus B: | in Porthill |
| Counties: | Boundary |
| Previous Type: | ID |
| Previous Route: | 200 |
| Next Type: | US |
| Next Route: | 2 |
| Tourist: | Part of the International Selkirk Loop |
State Highway 1 (SH-1) is a state highway in Boundary County, in the U.S. state of Idaho. It extends 11.185miles 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.[2] 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.[3] [4]
SH-1 runs 11.92miles from U.S. Route 95 (US-95) east of Copeland, north to BC 21 in Porthill. The route links Bonners Ferry, via US-95 south, Porthill, and Creston, BC.[5] The road is the only state highway in Boundary County, the two other highways are US-95 and US-2. The highway starts at an intersection with US-95 east of Copeland.[6] [7]
SH-1 was originally created in the 1920s as part of Sampson Trail B, which ran from Boise north to Lewiston, Coeur d'Alene, before entering British Columbia at Porthill.[8] Later in the mid-1930s, Idaho adopted a new numbered highway system with SH-1 as one of the first highways.[9] [10] The International Selkirk Loop, which uses SH-1, was formed in 1999.[11] The loop became an Idaho Scenic byway on January 21, 2004, as the Wild Horse Trail.[4]