| Castle Rock | |
| Elevation Ft: | 6340. |
| Elevation Ref: | [1] |
| Prominence Ft: | 520. |
| Isolation Mi: | 1.1 |
| Parent Peak: | Brighams Tomb (6,739 ft) |
| Map: | Utah#USA |
| Map Size: | 230 |
| Label Position: | top |
| Location: | Monument Valley San Juan County, Utah, U.S. |
| Range: | Colorado Plateau[2] |
| Coordinates: | 37.0326°N -110.0743°W |
| Coordinates Ref: | [3] |
| Topo: | USGS Monument Pass |
| Rock: | Sandstone |
| Type: | Butte |
| First Ascent: | 1960 |
| Easiest Route: | climbing |
Castle Rock is a 6340feet summit in San Juan County, Utah, United States.[3]
Castle Rock is situated 4miles north-northeast of the Monument Valley Tribal Park Visitor Center, on Navajo Nation land. It is an iconic landform of Monument Valley and can be seen from Highway 163. Precipitation runoff from this landform's slopes drains into the San Juan River drainage basin.[2] Topographic relief is significant as the summit rises 800abbr=offNaNabbr=off above the surrounding terrain in 0.25 mile (0.4 km). This landform's toponym has been officially adopted by the United States Board on Geographic Names.[3] It is so named because the butte resembles the silhouette of a castle.[4] The first ascent of the summit was made on May 8, 1960, by Harvey T. Carter, Layton Kor, and John Auld.[5] [6]
Castle Rock is composed of three principal strata. The bottom layer is slope-forming Organ Rock Shale, the next stratum is cliff-forming De Chelly Sandstone, and the upper layer is Moenkopi Formation. The rock ranges in age from Permian at the bottom to Triassic at the top. The buttes and mesas of Monument Valley are the result of the Organ Rock Shale being more easily eroded than the overlaying sandstone.[7]
Spring and fall are the most favorable seasons to visit Castle Rock. According to the Köppen climate classification system, it is located in a semi-arid climate zone with cold winters and hot summers. Summers average 54 days above 90°F annually, and highs rarely exceed 100°F. Summer nights are comfortably cool, and temperatures drop quickly after sunset. Winters are cold, but daytime highs are usually above freezing. Winter temperatures below 0°F are uncommon, though possible. This desert climate receives less than 10abbr=offNaNabbr=off of annual rainfall, and snowfall is generally light during the winter.[8]