| Mount Cirrus | |
| Elevation Ft: | 12808 |
| Elevation Ref: | [1] |
| Prominence Ft: | 400. |
| Isolation Mi: | 0.56 |
| Parent Peak: | Howard Mountain (12,826 ft) |
| Etymology: | Cirrus cloud |
| Country: | United States |
| State: | Colorado |
| Region: | Grand County / Jackson County |
| Region Type: | County |
| Part Type: | Protected area |
| Part: | Rocky Mountain National Park Never Summer Wilderness |
| Range: | Rocky Mountains Never Summer Mountains |
| Map: | Colorado#USA |
| Label Position: | right |
| Coordinates: | 40.4347°N -105.9019°W |
| Coordinates Ref: | [2] |
| Topo: | USGS Mount Richthofen |
| Rock: | shale and granodiorite[3] |
| Easiest Route: | Southwest Ridge [4] |
Mount Cirrus is a 12808feet mountain summit in Colorado, United States.
Mount Cirrus is situated on the Continental Divide along the boundary shared by Grand County and Jackson County.[5] It is the third-highest peak of the Never Summer Mountains which are a subrange of the Rocky Mountains.[6] The mountain is situated on the western boundary of Rocky Mountain National Park and is visible from Trail Ridge Road within the park. The west side of the peak is in the Never Summer Wilderness, on land managed by Medicine Bow–Routt National Forest. Precipitation runoff from the mountain's west slope drains into tributaries of the Michigan River and the east slope drains into headwaters of the Colorado River except a portion which is diverted by the Grand Ditch. The counterintuitive direction of water flow is because the Continental Divide forms a loop in this area, whereby the peak's west slope runoff flows to the Atlantic Ocean and the east slope to the Pacific. Topographic relief is significant as the summit rises 3600abbr=offNaNabbr=off above the Colorado River in 3miles and 2600abbr=offNaNabbr=off above the South Fork Michigan River in 1miles.
The mountain's toponym was applied in 1914 by James Grafton Rogers,[7] and was officially adopted in 1932 by the United States Board on Geographic Names.[2] Rogers also named Mount Cumulus and Mount Nimbus, with the three names referring to different types of common clouds. As President of the Colorado Geographic Society, Chairman of the Colorado Geographic Board, and President of the American Alpine Club, Rogers participated in naming many of Colorado's mountains.[8] The north ridge of Cirrus, officially named Hart Ridge, is named in remembrance of Eldon Charles Hart, Jr., of the Kansas Air National Guard, who was killed in the crash of his plane on this ridge on January 30, 1967, at age 26.[9]
According to the Köppen climate classification system, Mount Cirrus is located in an alpine subarctic climate zone with cold, snowy winters, and cool to warm summers.[10] Due to its altitude, it receives precipitation all year, as snow in winter, and as thunderstorms in summer, with a dry period in late spring.