| Sitting Bull Mountain | |
| Elevation Ft: | 7759 |
| Prominence Ft: | 599 |
| Isolation Mi: | 1.53 |
| Isolation Ref: | [1] |
| Parent Peak: | Plummer Mountain 7870 ft |
| Map: | Washington#USA |
| Country: | United States |
| State: | Washington |
| Region: | Snohomish / Chelan |
| Region Type: | County |
| Part Type: | Protected area |
| Part: | Glacier Peak Wilderness |
| Range: | Cascade Range |
| Coordinates: | 48.2276°N -120.9595°W |
| Topo: | USGS Suiattle Pass |
| Type: | Metamorphic brown Gneiss |
| Age: | Cretaceous |
| First Ascent: | 1921 party of The Mountaineers |
| Easiest Route: | Scrambling |
Sitting Bull Mountain is a 7759feet double summit mountain in the North Cascades of Washington state. The north summit is higher than the south peak (7680+ ft), and easier to climb (class 3 vs. class 4), however neither peak sees much climbing activity. Sitting Bull Mountain is located 2.1miles northwest of Suiattle Pass in the heart of the Glacier Peak Wilderness. Its nearest higher peak is Plummer Mountain, 1.51miles to the south-southwest. The mountain is situated on the crest of the Cascade Range, on the shared border of Snohomish County and Chelan County. Precipitation runoff from Sitting Bull Mountain drains east into Agnes Creek which is a tributary of the Stehekin River, or west into Canyon Creek which is a tributary of the Suiattle River.
Subduction and tectonic activity in the area began during the late cretaceous period, about . The area was previously an oceanic environment, consisting mainly of sedimentary and volcanic rocks.[2] Extensive volcanic activity began to take place in the oligocene, about .[3] However, mountain building in the area did not begin until the miocene, approximately .[4] Sitting Bull Mountain is located in the Cloudy Pass batholith, an intrusive formation that was formed approximately, during the early miocene.[5] Glacier Peak, a stratovolcano that is south of Sitting Bull Mountain, began forming in the mid-Pleistocene.[6] Due to Glacier Peak's proximity to Sitting Bull Mountain, volcanic ash is quite common in the area.
Throughout the ice age, the North Cascades were mostly covered in thick glaciers, extending to near Puget Sound. Glaciation was most prevalent approximately, and most valleys were ice-free by .[7] As a result, valleys in the area are deep and u-shaped, and mountains tend to be rocky, with steep slopes and narrow summits.
Sitting Bull Mountain is located in the marine west coast climate zone of western North America.[8] Most weather fronts originating in the Pacific Ocean travel northeast toward the Cascade 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.[2] Because of maritime influence, snow tends to be wet and heavy, resulting in high avalanche danger.[2] 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.[2] Due to its temperate climate and proximity to the Pacific Ocean, areas west of the Cascade Crest very rarely experience temperatures below 0°F or above 80°F.[2] The months of July through September offer the most favorable weather for viewing or climbing this peak.