| Sperry Peak | |
|---|---|
 North aspect of Sperry Peak | |
| Highest point | |
| Elevation | 6,120 ft (1,865 m)[1] |
| Prominence | 720 ft (219 m)[1] |
| Parent peak | Vesper Peak[2] |
| Isolation | 0.73 mi (1.17 km)[2] |
| Coordinates | 48°00′57″N121°30′09″W / 48.015894°N 121.502633°W /48.015894; -121.502633[1] |
| Geography | |
  Sperry Peak Location in Washington Show map of Washington (state) Sperry Peak Sperry Peak (the United States) Show map of the United States | |
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| Interactive map of Sperry Peak | |
| Country | United States |
| State | Washington |
| County | Snohomish |
| Parent range | North Cascades Cascade Range |
| Topo map | USGSSilverton |
| Geology | |
| Rock age | 260 to 370 million years |
| Rock type(s) | metamorphosedsandstoneshale,conglomerate[3] |
| Climbing | |
| First ascent | 1927 |
| Easiest route | Scrambling Southwest slope |
Sperry Peak is a 6,120+ ft (1,870+ m) mountainsummit inSnohomish County ofWashington state.
Sperry Peak is located 2.5 miles (4.0 km) east ofBarlow Pass near theMountain Loop Highway and theMonte Cristo area, on land managed by theMount Baker-Snoqualmie National Forest. It is set in theSouth Fork Stillaguamish River Valley near the western edge of theNorth Cascades. The nearest higher neighbor isVesper Peak, 0.74 miles (1.19 km) to the west, with a high connecting ridge between the two.Topographic relief is significant as the summit rises over 3,900 feet (1,189 meters) above the South Fork Stillaguamish in approximately one mile (1.6 km).
The peak was named forA. D. (Dick) Sperry, aSilverton miningprospector during the 1890s.[3] The Dick Sperry Picnic Area is near the historic site of the abandoned Sperry-Iverson mine near Silverton. The mountain's toponym has been officially adopted by theUnited States Board on Geographic Names.[4] Thefirst ascent of the summit was made in 1927 by Norval Grigg and Art Winder.[3]
Sperry Peak is located in themarine west coast climate zone of westernNorth America.[3] Mostweather fronts originating in the Pacific Ocean travel northeast toward theCascade Mountains. As fronts approach the North Cascades, they are forced upward by the peaks of the Cascade Range (orographic lift), causing them to drop their moisture in the form of rain or snowfall 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] 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] 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] 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, ridges, and deepglacial valleys. Geological events occurring many years ago created the diverse topography and drastic elevation changes over the Cascade Range leading to various climate differences.
The history of the formation of the Cascade Mountains dates back millions of years ago to the lateEocene Epoch.[5] With theNorth American Plate overriding thePacific Plate, episodes ofvolcanic igneous activity persisted.[5] In addition, small fragments of theoceanic andcontinental lithosphere calledterranes created theNorth Cascades about 50 million years ago.[5]
During thePleistocene period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris.[5] 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.
