[4] The Osterhout milkvetch is a herbaceous, or non-woody, plant belonging to the pea family.

[2][3] It has several bright green, slender, erect stems that range from 30.48–100 cm (12–40 in) tall.

The Osterhout milkvetch can be distinguished from A. pattersonii by its long flattened hanging fruit.

[3][2] The Osterhout milkvetch reproduces through seeds made viable through outcrossing and self-pollination.

Like other plants in the Astragalus genus, the Osterhout milkvetch experiences low fecundity.

[2] Primary pollinators of the Osterhout milkvetch include honey bees (Apis mellifera), bumblebees (Bombus sp.

[2] It grows on shaley slopes at elevations ranging from 2,26 - 2,408 m (7,400-7,900 ft) above sea level.

This region includes plants such as big sagebrush (Artemisia tridentata), yellow rabbitbrush (Chrysothamnus viscidiflorus), broom snakeweed (Gutierrezia sarothrae), winterfat (Krascheninnikovia lanata), spiny phlox (Phlox hoodii), short-stem buckwheat (Eriogonum brevicaule), and western wheatgrass (Pascopyrum smithii).

The Osterhout milkvetch is only found in a small area in Middle Park Colorado, near the town of Kremmling.

[2] In total, the plant has five small, scattered populations within a 13 km (8 mi) radius.

[3] In 1988 there were an estimated 25,000 to 50,000 individuals in the Osterhout milkvetch species gathered from six documented occurrences.

[2] In 1995, one of these populations and a large part of its range was lost with the filling of a new reservoir on the Muddy Creek.

New utility installations, access roads, off-highway vehicle recreation also pose a threat.

[2] The habitat is also threatened by reservoir operations and expansion, oil and gas drilling, and livestock grazing.

Invasive plants not native to the area and climate change also pose a threat.

Concerns about the development of the reservoir included placing a dam, recreational use, mining, and geographically isolated populations.

[2] The 1992 Recovery Plan aimed for the “conservation of existing populations for the foreseeable future”.

The 1992 Recovery Plan also had three main priorities:[8] 1) Action has to be taken to prevent extinction of irreversible decline in the foreseeable future.

2) To prevent decline in population and habitat quality or any other large negative impact short of extinction.

There were several recovery tasks set:[8] 1) To inventory any remaining potential habitat.

On private lands, there needs to be an establishment of state natural resource areas.

The critical habitat is the 13 km (8 mi) radius near the town of Kremmling where the Osterhout milkvetch is found.