Pawnee National Grassland

Pawnee National Grassland
The Pawnee Buttes in Pawnee National Grassland
Pawnee National Grassland
Location	Weld County, Colorado, United States
Nearest city	Greeley, Colorado
Coordinates	40°48′29″N 103°59′21″W / 40.80806°N 103.98917°W / 40.80806; -103.98917[1]
Area	193,060 acres (781.3 km2)[2]
Established	1960
Governing body	U.S. Forest Service
Website	Arapaho & Roosevelt National Forests and Pawnee National Grassland

Pawnee National Grassland is a

Recreational activities on the Pawnee Grasslands have been somewhat curtailed over the last 10 years due to the discovery of extractable oil and natural gas. According to the US Forest Service, there are 63 active vertical oil and natural gas wells, and less than 3,000 acres of the 193,060 acres is protected from drilling.[4]

Geology

The grasslands is a joining of two soil types. In the east are prairie soils that are deep, and dark or reddish. From the west are

The grassland is a part of the short grass plains of North America. The best example of this ecosystem are preserved around the Pawnee Buttes where grazing and intensive agriculture have had less impact. There are eleven vegetation zones represented with the most unique being the scarp woodlands on the north face of the buttes. Typical of higher elevations, there are limber pines and relicts of an ice-age forest.^[5]

The wildlife of the grasslands is best represented near the buttes, with

• Short grass prairies cover the open flatlands at the below the buttes and the escarpments. They are dominated by blue grama and buffalo grass. Associated plants include the thread-leaf sedge, ring muhly, western wheatgrass, and the prickly pear cactus. The western wheatgrass dominates in "buffalo wallows" or other low patches.^[5]
• Mixed prairie are the lighter and more sandy soils, found on the heights. The dominant plants are the
  milkvetches, and locoweeds are highly visible. The mixed prairie has the greatest variety of plants.^[5]
• The little bluestem is found across the entire grasslands, but it dominates in localized plots. These are in the swales and along north facing slopes where the shade will retain water longer. The same applies to soils that are sandy and gravelly. These areas are populated by little bluestem and a mix of Canada rye, phlox, borges, and a mix of grasses and forbs.^[5]
• Shrub steppe areas are similar to the short grass and mixed prairie, but with a greater alkalinity. Thus, the fourwing saltbush dominates these areas. They are found along the bottom of the escarpments. There is a variety of shrubs and forbs, but the key plants will be the saltbush and other alkaline loving plants, i.e., small soapweed and common winterfat.^[5]
• Arroyos form near the escarpments along major drainage. Arroyos can be up to 30 feet (9.1 m) deep. There is no standing water, but the volume of water from each rain event allows the soils to hold moisture for a longer period. Here the dominant plants are larger shrubs or small trees, Rocky Mountain juniper and choke cherry. The moister soils allow for current, gooseberry, and other shrubs similar to the breaks environment. There will also be little bluestem and Canada rye found.^[5]
• Clay barrens are dominated by the eroding Brule Formation. Here
  Indian rice grass, Penstemon, and evening primrose. Where there is active erosion, there are no plants.^[5]
• Break shrub are areas of broken rock. They can be along the upper edge of an escarpment, shelves on vertical slopes or rocky areas at the bottom of a cliff. These areas provide tenuous holds and deep rooting plants dominate. The
  roses.^[5]
• Scarp woodlands are found on the north-facing cliff edges and rocky areas. They are in the narrow canyons draining northwards, providing water, and protection against evaporation. Here larger trees can take root, such as limber pine, small ponderosa pines, and Rocky Mountain juniper. These are in addition to the break shrubs found on less protected northern slopes.^[5]
• Willow Spring is the only natural water source near the buttes. Here water loving peach-leaf willow abound along with a variety of sedges.^[5]
• Bare rocks offer a limited chance for growth to crustose lichens, Caloplaca, and Lanconroa calcarea.^[5]
• Road edges receive runoff from the hard pack road surface. Invasive plants move into the initial disturbance and find adequate water to remain. The dominant plants are:
  Indian ricegrass, sedges, grasses, and forbs.^[5]

Wildflowers bloom from April through September. The best locations for viewing wildflowers are near rocky outcrops or wet potholes, such as are found near the Pawnee Buttes.^[6]

Gallery

• 
  Colorado, with Pawnee National Grassland highlighted in red.
• 
  Weld County, Colorado with Pawnee National Grassland highlighted in red.
• 
  One of the signs marking the entrance to the grassland. This one is at the west side along State Highway 14.
• 
  Rock formation near the Pawnee Buttes.
• 
  Sunrise over the grassland.
• 
  A gully near the Pawnee Buttes.
• 
  View of Pawnee National Grassland from County Rd 116 in February.
• 
  A thundercloud rolling in over the prairie.
• 
  Uninterrupted prairie
• 
  Oil wells on Colorado State Highway 14

See also

Wikimedia Commons has media related to Pawnee National Grassland.

• Chalk Bluffs Natural Area
• List of protected grasslands of North America

References

External links

• Arapaho and Roosevelt National Forests and Pawnee National Grassland (United States Forest Service)