Siskiyou Summit

Siskiyou Summit
Siskiyou Mountain Summit marker at southbound truck brake check area
Elevation	4,310 ft (1,314 m)
Traversed by	Interstate 5
Location
Location	Jackson County, Oregon, United States
Range	Siskiyou Mountains
Coordinates	42°3′34″N 122°36′28.75″W

Siskiyou Summit (or Siskiyou Mountain Summit) is a mountain pass that carries Interstate 5 (I-5) through the Siskiyou Mountains near the border between the U.S. states of California and Oregon. The summit is located on the Oregon side, approximately 4 miles (6.4 km) north of the state line, and, at 4,310 feet (1,310 m), is the highest point on Interstate 5. The pass features some of the steepest grades in the Interstate Highway System. Siskiyou Pass is also crossed by the Central Oregon and Pacific Railroad, originally the main line of the Oregon and California Railroad. It was bypassed by a shorter and less steep route via Klamath Falls, known as the Natron Cutoff, in 1926.

"Siskiyou Summit" is distinct from the "Siskiyou Pass" that was the highest point of U.S. Route 99. U.S. Route 99 was replaced by Interstate 5 by 1964 but the pass on I-5 is commonly also referred to as "Siskiyou Pass".