Montana Field Guide

Great Plains Badlands are typically sparsely vegetated (<10% total vegetation cover) and easily recognized by the rugged, eroded, and often colorful land formations, and the relative absence of vegetative cover. The sloping, eroding sites, lack of soil development, and lack of available moisture for plants limit the species that can grow on these sites. Small areas with shallower slopes may have moderate vegetation cover. Dominant plants are usually low shrubs and forbs, though grasses can dominate some areas. This group generally occurs within the mixedgrass prairie and sand prairie communities of eastern Montana.

This Group encompasses the Great Plains Badlands and the Shale Badland Ecological Systems.

Highly Eroded Landforms; Sparsely-Vegetated with <10% Vegetated Cover; Poorly Developed Soils; Great Plains Region

This system is scattered throughout the Great Plains region of eastern Montana where eroded landscapes limit the ability of vegetation to thrive. This system is well represented in Makoshika State Park near Glendive, in the Terry Badlands north of the Yellowstone River, and at scattered locations along tributaries of the Missouri river in the northwestern Great Plains.

In Montana, G566 occurs in Level III Ecoregions 42 (Northwestern Glaciated Plains) and 43 (Northwestern Great Plains).

In MT, G566 occurs in these Major Land Resource Areas: 52-Brown Glaciated Plains, 53A-Northern Dark Brown Glaciated Plains, 58A,B,C,D-Northern Rolling High Plains, and 60B - Pierre Shale Plains.

Large Patch

These systems are primarily found on eroded uplands, slopes, and creek bottoms throughout the northwestern Great Plains region of Montana. Soils are extremely dry and easily erodible consolidated clayey soils with bands of sandstone or isolated consolidates. Dominant soil types are in the order Entisols. The steep and deeply eroded slopes of badland habitats tend to be harsh environments, which support only species uniquely adapted to these conditions (Brown 1971). The sedimentary parent material of exposed rocks and the resultant eroded clay soils are derived from Cretaceous sea beds and are often fossil-rich. In these arid to semi-arid climates, infrequent but heavy rains cause rapid erosion, leaving a highly dissected landscape with a complex dendritic drainage pattern. Precipitation in these areas generally ranges from 10 to 19 inches with two-thirds coming during the summer and most of the other third in the spring. The growing season is on average 115 days, although the growing season ranges from 100 days on the Canadian border to 130 days on the Wyoming border.

Vegetation within badland areas is generally sparse, often with less than 10% of the total land cover occupied by vegetation, locally some areas will have higher cover. In northeastern Montana, vegetation cover is at the higher end, but in southeastern Montana, portions of this system may have little to no vegetation. Local variations in geology, topography, and soil contribute to unique plant communities and vegetation composition (Brown 1971). Common plant communities include those dominated or with significant components of Greasewood (Sarcobatus vermiculatus), Gardner’s saltbush (Atriplex gardneri), Small-flowered Buckwheat (Eriogonum pauciflorum) - Broom Snakeweed (Gutierrezia sarothrae) or Longleaf Wormwood (Artemisia longifolia).

Graminoid cover is very sparse, but may include Western Wheatgrass (Elymus smithii), Bluebunch Wheatgrass (Elymus spicatus), and Indian Ricegrass (Oryzopsis hymenoides). Common forbs include Small-flowered Buckwheat (Eriogonum pauciflorum), Broom Snakeweed (Gutierrezia sarothrae), Hooker’s sandwort (Arenaria hookeri), budsage (Artemisia spinescens), curlycup gumweed (Grindelia squarrosa), and Nutall’s povertyweed (Monolepis nuttalliana). Other shrubs that may be present include Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), silver sagebrush (Artemisia cana), Rubber Rabbitbrush (Ericameria nauseosa), and shadscale (Atriplex confertifolia).

In Montana, this group is represented by 4 Alliances and 6 Associations within the National Vegetation Classification, which likely represents most of the diversity of these sparsely-vegetated sites, though additional types may exist.

This system can occur where the land lies well above its local base level or below and is created by several factors, including elevation, rainfall, carving action of streams, and parent material. Vegetation communities associated with this ecological system are adapted to soils that are dry throughout the growing season. Typically soils of the badlands ecosystem are easily erodible consolidated clay or sandstone outcrops. They may also occur on shallow entisols, with parent material and/or bedrock formation close to the surface. These highly erodible soils can be strongly influenced by infrequent but heavy rains.

Land use is generally limited in these areas due to the highly erodible, clay soils and sparse vegetation cover. Off-road vehicle use and grazing may impact soils and plant communities. Because of the erodible soils, these areas can be easily damaged by off-road vehicle use. Limiting such use to specified areas may be beneficial for preserving more sensitive communities, such as the Birdsfoot Sagebrush- Gardner’s saltbush (Artemisia pedatifida - Atriplex gardneri) shrubland.

Restricting off-road use and limiting or removing grazing may be necessary where these activities have negatively impacted sensitive resources or vegetation growth.

J. Drake 2011

S. Mincemoyer, E. Luther, L. Vance

12/5/2024