Highway 31 is a minor north–south highway through the Selkirk Mountains in British Columbia, Canada. The highway first gained its number in 1973, and it is one of the few numbered highways in the province that is not fully paved. Highway 31 has a total distance of 175 km (109 mi) — 37 km (23 mi) along Kootenay Lake between Balfour (a junction with Highway 3A) and Kaslo (a junction with Highway 31A), 106 km (66 mi) north along Kootenay Lake north of Kaslo, then the Duncan and Lardeau Rivers and the north shore of Trout Lake, and 32 km (20 mi) between the northwest end of Trout Lake and Galena Bay, where it ends at Highway 23.

Highway 31
Route information
Maintained by British Columbia Ministry of Transportation and Infrastructure
Existed	1973–present
Highway 31
Length	175 km[1] (109 mi)
South end	Hwy 3A in Balfour
Major intersections	Hwy 31A in Kaslo
North end	Hwy 23 in Galena Bay
Highway 31A
Length	47 km[1] (29 mi)
West end	Hwy 6 in New Denver
East end	Hwy 31 in Kaslo
Location
Country	Canada
Province	British Columbia
Highway system
British Columbia provincial highways
← Hwy 30 → Hwy 33

The highway is a gravel road between Meadow Creek at the north end of Kootenay Lake and Trout Lake. Care should be taken when driving the route as it is narrow and has drop offs into Trout Lake north of Gerrard.

The section between Lardeau and Gerrard was possibly a part of a railway. The railway was converted into a highway in 1942 or early 1943 as part of a rail-to-road conversion project. The work took only two months to complete.^[2]