| Spire Mountain | |
|---|---|
 ENE aspect, from West Cady Ridge | |
| Highest point | |
| Elevation | 6,213 ft (1,894 m)[1] |
| Prominence | 1,853 ft (565 m)[1] |
| Parent peak | Gunn Peak (6,244 ft)[2] |
| Isolation | 3.92 mi (6.31 km)[2] |
| Coordinates | 47°51′56″N121°24′22″W / 47.865634°N 121.406039°W /47.865634; -121.406039 |
| Geography | |
  Spire Mountain Location in Washington Show map of Washington (state) Spire Mountain Spire Mountain (the United States) Show map of the United States | |
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| Interactive map of Spire Mountain | |
| Location | Snohomish County,Washington, US |
| Parent range | Cascade Range |
| Topo map | USGSBaring |
| Geology | |
| Rock type | gabbro[3] |
| Climbing | |
| First ascent | May 1934, Dwight Dean, Kenneth Chapman[4][3] |
| Easiest route | class 4-5[3] |
Spire Mountain is a 6,213-foot (1,894-metre)Cascade Range mountain summit located inSnohomish County,Washington.[5] It is set 7 miles (11 km) northeast of the town ofIndex, and 4 miles (6.4 km) north-northeast ofGunn Peak, its nearest higher neighbor. This mountain is situated in theWild Sky Wilderness, on land managed byMount Baker-Snoqualmie National Forest. Precipitationrunoff from the mountain drains into tributaries of theSkykomish River. Thefirst ascent of the highest Northwest Spire was made in 1934 by Dwight Dean and Kenneth Chapman. The first ascent of the Central Spire (6,200-ft) was made in 1938 by Karl Boyer, Lyman Boyer, and David Lind.[3] The Southeast Spire is estimated as 6,185 feet in elevation.[3]
Spire Mountain is located in themarine west coast climate zone of westernNorth America.[3] Mostweather fronts originate in thePacific Ocean, and travel northeast toward theCascade Mountains. As fronts approach theNorth Cascades, they are forced upward by the peaks of the Cascade Range (Orographic lift), causing them to drop their moisture in the form ofrain orsnowfall onto the Cascades. As a result, the west side of the North Cascades experiences high precipitation, especially during the winter months in the form of snowfall.[3] Because ofmaritime influence, snow tends to be wet and heavy, resulting in highavalanche danger.[3] Due to its temperate climate and proximity to the Pacific Ocean, areas west of the Cascade Crest very rarely experience temperatures below 0 °F (−18 °C) or above 80 °F (27 °C).[3] During winter months, weather is usually cloudy, but, due to high pressure systems over the Pacific Ocean that intensify during summer months, there is often little or no cloud cover during the summer.[3] The months July through September offer the most favorable weather for viewing or climbing this peak.
The North Cascades features some of the most rugged topography in theCascade Range with craggy peaks, spires, ridges, and deepglacial valleys. Geological events occurring many years ago created the diverse topography and drastic elevation changes over the Cascade Range leading to the various climate differences.
The history of the formation of the Cascade Mountains dates back millions of years ago to the lateEocene Epoch.[6] With theNorth American Plate overriding thePacific Plate, episodes ofvolcanic igneous activity persisted.[6] In addition, small fragments of theoceanic andcontinental lithosphere calledterranes created theNorth Cascades about 50 million years ago.[6]
During thePleistocene period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris.[6] The U-shaped cross section of the river valleys is a result of recent glaciation.Uplift andfaulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the North Cascades area.
