Washington State Route 100

State Route 100
SR 100 highlighted in red
Route information
Auxiliary route of US 101
Maintained by WSDOT
Length	4.68 mi[1] (7.53 km)
Existed	1991[2]–present
Tourist routes	Lewis and Clark Trail
Major junctions
CCW end	US 101 in Ilwaco
CW end	SR 100 in Ilwaco
Location
Country	United States
State	Washington
County	Pacific
Highway system
State highways in Washington Interstate US State Scenic Pre-1964 1964 renumbering Former
← SR 99 → US 101

State Route 100 (SR 100) is a 4.68-mile-long (7.53 km) state highway in the U.S. state of Washington, serving Cape Disappointment State Park in Pacific County. The highway travels counterclockwise from U.S. Route 101 (US 101) in Ilwaco south to Cape Disappointment and north to an intersection with itself in Ilwaco. SR 100, part of the Lewis and Clark Trail Scenic Byway, serves as a loop route and has a spur route that serves the state park and a Coast Guard station. SR 100 was established in 1991 on the existing North Head Road, which was a paved county road by the late 1950s. The highway was washed away during a 1994 winter storm and had its spur route shortened in 2006.