| Corteo Peak | |
| Elevation Ft: | 8107 |
| Elevation Ref: | [1] |
| Prominence Ft: | 652 |
| Isolation Mi: | 1.67 |
| Parent Peak: | Black Peak (8,970 ft) |
| Map: | Washington#USA |
| Map Size: | 270 |
| Label Position: | right |
| Country: | United States |
| State: | Washington |
| Region: | Chelan |
| Region Type: | County |
| Part Type: | Protected area |
| Part: | North Cascades National Park Stephen Mather Wilderness |
| Range: | North Cascades |
| Coordinates: | 48.5045°N -120.7883°W |
| First Ascent: | July 1935, John Lehmann and Hermann Ulrichs[2] |
| Easiest Route: | Scrambling, |
| Topo: | USGS Mount Arriva |
Corteo Peak is an 8107feet mountain summit located on the eastern boundary line of North Cascades National Park in Washington state. It is situated west of Rainy Pass in the North Cascades Range. Remnants of the retreating Lewis Glacier hang on its north flank. Topographic relief is significant as the summit rises approximately 3200abbr=offNaNabbr=off above Maple Creek in one mile (1.6 km) and 2400abbr=offNaNabbr=off above Lewis Lake in one-half mile (0.8 km). The nearest higher peak is Black Peak, 1.67miles to the northwest. Corteo Peak and nearby Mount Benzarino were named by Forest Service surveyor, Lage Wernstedt, after Basque sheepherders he met near these two mountains.[3]
Corteo Peak is located in the marine west coast climate zone of western North America.[2] 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. 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]
The North Cascades features some of the most rugged topography in the Cascade Range with craggy peaks, ridges, and deep glacial valleys. The history of the formation of the Cascade Mountains dates back millions of years ago to the late Eocene Epoch.[4] With the North American Plate overriding the Pacific Plate, episodes of volcanic igneous activity persisted.[4] In addition, small fragments of the oceanic and continental lithosphere called terranes created the North Cascades about 50 million years ago.[4]
During the Pleistocene period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris.[4] The U-shaped cross section of the river valleys is a result of recent glaciation. Uplift and faulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the North Cascades area.