Siskiyou Summit

Coordinates: 42°3′38″N 122°36′21″W / 42.06056°N 122.60583°W / 42.06056; -122.60583
From Wikipedia, the free encyclopedia
Siskiyou Summit
Siskiyou Mountain Summit marker at southbound truck brake check area
Elevation4,310 ft (1,314 m)
Traversed by I-5
LocationJackson County, Oregon,
United States
RangeSiskiyou Mountains
Coordinates42°3′38″N 122°36′21″W / 42.06056°N 122.60583°W / 42.06056; -122.60583

Siskiyou Summit (also Siskiyou Mtn. Summit; also referred to as Siskiyou Pass) is a summit (high point) on Interstate 5 (I-5) in the U.S. state of Oregon. It is distinct from Siskiyou Pass, which is a nearby, historical mountain pass.[1][2] Siskiyou Summit is situated in the Siskiyou Mountains, approximately 4 miles (6.4 km) north of the California border.[3] At 4,310 feet (1,310 m), it is the highest point on Interstate 5.[4] When the highway was rebuilt on its current alignment, road cutting lowered the elevation of the summit by 49 feet (15 m).[5]


The Siskiyou Mountains form the watershed boundary between the Klamath and Rogue Rivers and are also a rough natural separator between Oregon and California. The summit on Interstate 5 is about 25 miles (40 km) north of Yreka, California, and 0.5 miles (0.80 km) east of the historical Siskiyou Pass, the most used mountain pass in the state.[2] The Pacific Crest National Scenic Trail crosses the highway here on the way to Mexico from Canada.[6]


Weather station at the summit of the old road.

The road over Siskiyou Summit is typically closed to traffic for many days during winter due to severe weather conditions. At times, it can be closed during winter even when the weather is fine.[7] Regardless, weather data is important to those involved in transportation over the summit. Average monthly temperatures and rainfall are given in the table below. Snow generally falls during the months of November through April, typically peaking with four such days in December. The wind speed over the course of a year varies from an average of 13 km/h (8.1 mph) in May to episodes of 80 km/h (50 mph). The average number of rainy days per month varies from 11 in December to only two in June, August and September.[8]

Climate data for Siskiyou-Summit
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Average high °C (°F) 8
Average low °C (°F) 0
Average precipitation mm (inches) 32
Source: [8]


Left: I-5 at Siskiyou Summit (2010); right: Snowplow clearing snow on Siskiyou Summit.

The Hudson’s Bay Company carved a route from Oregon to California during their hunt for furs and pelts following Native American trails. HBC developed the Siskiyou Trail in 1827, which included crossing Siskiyou Summit. In the 1830s, Ewing Young, using horses and mules, led hundreds of cattle over the Siskiyou Trail, necessitating its widening; this process, which took three months to complete, linked the Shasta Valley in California with the Rogue Valley in Oregon. Scientists and cartographers of the United States Exploring Expedition carried out studies along this trail in 1841, while miners of the California Gold Rush traversed the trail to reach the gold fields. In the 1860s, the trail was widened so that stagecoaches could easily traverse it. The first telegraph line was added in 1864. Only in the 1960s did it become the modern highway now designated Interstate 5.[9][self-published source]


The summit "towering 4310 ft straight up and straight down with curves thrown in for variety", has enough space for parking two lanes of rigs on both flanks of the road. Since the gradient is about 6%, it is a preferred place for truckers to park, refuel, check the condition of their vehicles, and rest. The road down from the summit on the north side is steep and winding. During winter, reaching the summit can be a challenge due to snow and ice on the pavement.[10] In 2008, after the Central Oregon and Pacific Railroad rail link between Medford, Oregon and Weed, California was closed, the highway saw greater use by truckers to carry timber and finished products. In order to reduce reliance on this hazardous mountain road and to reduce the expense of highway transport, proposals were made to reopen the rail link.[11] The rail line over the pass was reopened in 2015.[12]

See also[edit]


  1. ^ "ODOT advisory on Siskiyou Summit, also called Siskiyou Pass" (PDF). Oregon Department of Transportation. Archived from the original (PDF) on 16 July 2012. Retrieved 21 May 2013.
  2. ^ a b LaLande, Jeffrey M. "Siskiyou Pass". The Oregon Encyclopedia. Portland State University. Retrieved 22 May 2013.
  3. ^ U.S. Geological Survey Geographic Names Information System: Siskiyou Summit
  4. ^ "Interstate 5: Interesting Facts". Oregon Department of Transportation. Retrieved 2007-09-26.
  5. ^ Karen Cleland; Donald Y. East (9 May 2007). Yreka. Arcadia Publishing. pp. 24–. ISBN 978-0-7385-4735-0.
  6. ^ In Search of America's Heartbeat. Mill City Press, Inc. 31 December 2007. pp. 23–. ISBN 978-1-934248-36-2.
  7. ^ "Lonely Planet review for Siskiyou Summit". Lonely Planet. Retrieved 24 May 2013.
  8. ^ a b "Local Weather Siskiyou Summit Climate History". Retrieved 23 May 2013.
  9. ^ Howard R. Plank; calibre (0.7.22) [1] (13 December 2010). The Central Sacramento Valley Story: Reclamation, Irrigation, Farms, Rice, and Machinery. Xlibris Corporation. pp. 30–. ISBN 978-1-4568-2711-3. {{cite book}}: External link in |author2= (help)
  10. ^ Sharon St. James (15 October 2009). Another Chance. AuthorHouse. pp. 201–. ISBN 978-1-4490-2175-7.
  11. ^ "Siskiyou Summit Railroad Revitalization" (PDF). State of Oregon. Archived from the original (PDF) on 2013-02-05. Retrieved 18 Jan 2019.
  12. ^ Aleshire, Ilene (11 November 2015). "S. Oregon railroad line operating again after 7 year closure". The Register-Guard. Eugene, OR. Archived from the original on 17 June 2018. Retrieved 16 June 2018.