Arthur's Rock

Arthur's Rock
Arthur's Rock
	Arthur's Rock rises steeply from the Great Plains in Lory State Park outside of Fort Collins, Colorado. The rock that composes it is over 1.7 billion years old (August 31st, 2023)
Highest point
Elevation	2,066.544 m (6,780.00 ft)
Coordinates	40°34′06″N 105°11′17″W / 40.56828°N 105.18813°W
Geography
	Arthur's Rock Colorado, United States

Arthur's Rock is a 6,780 foot (2,066.5 meter) pillar in the foothills of the Colorado Front Range, near Fort Collins, Colorado.^[1]

Etymology

The name "Arthur's Rock" comes from Arthur Howard, who owned the rock and its surroundings before the establishment of Lory State Park.^[2]

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.^[3]

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. ^[4] This rock is exceptionally old.

Ecology

Arthur's Rock exists at the intersection between the shortgrass prairie of the Great Plains and the Pinyon–juniper woodland of the Front Range Foothills.^[5] 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 (Bouteloua gracilis), Buffalo Grass (Bouteloua dactyloides) and Western Wheatgrass (Pascopyrum smithii). Rabbitbrush, sagebrush and prickly pear (Opuntia sp.) are common among grasses.^[6]

A number of wildflowers occur on and around Arthur's Rock like yarrow (Achillea millefolium), prairie sunflower (Helianthus petiolaris), common sunflower (Helianthus annuus), prairie bluebell (Mertensia lanceolata) and Rocky Mountain bee plant (Cleomella serrulata).

References

^ "Geographic Names Information System". edits.nationalmap.gov. Retrieved 2024-09-04.
^ "Arthur's Rock - Peer to Peer Dialogue Program". peertopeer.colostate.edu. About Arthur's Rock. Retrieved 2024-09-04.
^ "Lory-State-Park-Brochure.pdf". cpw.widen.net. Retrieved 2024-09-04.
^ MOEGLIN, THOMAS DEAN (1978-01-01). "GEOMORPHIC DEVELOPMENT ON THE LOG CABIN BATHOLITH, LARIMER COUNTY, COLORADO". ETD collection for University of Nebraska-Lincoln: 1–109.
^ Vestal, Arthur G. (1917). "Foothills Vegetation in the Colorado Front Range". Botanical Gazette. 64 (5): 353–385. ISSN 0006-8071.
^ Vickery, John C. "Lory State Park Botanical Survey, 2021-2023 (Larimer County, Colorado, USA)". researchgate.net. Colorado Parks and Wildlife. pp. 20–38.

[1] "Geographic Names Information System". edits.nationalmap.gov. Retrieved 2024-09-04.

[2] "Arthur's Rock - Peer to Peer Dialogue Program". peertopeer.colostate.edu. About Arthur's Rock. Retrieved 2024-09-04.

[3] "Lory-State-Park-Brochure.pdf". cpw.widen.net. Retrieved 2024-09-04.

[4] MOEGLIN, THOMAS DEAN (1978-01-01). "GEOMORPHIC DEVELOPMENT ON THE LOG CABIN BATHOLITH, LARIMER COUNTY, COLORADO". ETD collection for University of Nebraska-Lincoln: 1–109.

[5] Vestal, Arthur G. (1917). "Foothills Vegetation in the Colorado Front Range". Botanical Gazette. 64 (5): 353–385. ISSN 0006-8071.

[6] Vickery, John C. "Lory State Park Botanical Survey, 2021-2023 (Larimer County, Colorado, USA)". researchgate.net. Colorado Parks and Wildlife. pp. 20–38.

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