Facts 

Overview
Tunnel under Knapps Hill on Alt US 97
Location
Chelan County, Washington
Status
Open to traffic
History
Built 1936
Design
Tunnel
Dimensions
Total length: 788.1 ft.
Inventory number
BH 34150 (Bridgehunter.com ID)
Inspection
Average daily traffic (as of 2002)
3,427

Categories 

Built 1936 (486)
Built during 1930s (5,160)
Chelan County, Washington (16)
Open (21,663)
Owned by state (6,563)
Total length 500-1000 feet (1,002)
Tunnel (257)
US 97 (5)
Washington (549)