Arthur's Rock
Arthur's Rock is a 6,780 foot pillar in the foothills of the Colorado Front Range, near Fort Collins, Colorado.
Etymology
The name "Arthur's Rock" comes from Arthur Howard, who owned the rock and its surroundings before the establishment of Lory State Park.Geography
Arthur's Rock is located directly outside of downtown Fort Collins, Colorado and is easily visible from much of the town and the campus of Colorado State University.It is located within Lory State Park, a 2,574 acre wilderness park comprising the western side of Horsetooth Reservoir. A number of single track hiking and biking trails provide access to the summit and surroundings of Arthur's Rock. The trail to the top of the rock is among the most popular in the park.
The area receives a moderate amount of snowfall between the months of October and May.
Geology
Similar to nearby Horsetooth Mountain, Arthur's Rock is composed of 1.7 billion year-old pegmatite, a type of intrusive igneous rock.The rock that now forms the summit was originally a subterranean pluton, a part of the wider Log Cabin Batholith that covers much of the area currently. Over the millennia, layers of sedimentary rock have been eroded away, leaving the hard pegmatite exposed. This rock is exceptionally old.
Ecology
Arthur's Rock exists at the intersection between the shortgrass prairie of the Great Plains and the Rocky Mountain ponderosa pine forest of the Front Range Foothills. Higher elevations on the mountain show species characteristic of montane ecosystems like blue spruce.Lower elevations in the area of the mountain are host to prairies composed of Blue Grama, Buffalo Grass and Western Wheatgrass. Rabbitbrush, sagebrush and prickly pear are common among grasses.
A number of wildflowers occur on and around Arthur's Rock like yarrow, prairie sunflower, common sunflower, prairie bluebell and Rocky Mountain bee plant.