It is interesting how the Missouri River supports so many rare, threatened and endangered species.

Beautiful flower. It grows in areas where there are rocks and where no other flower will grow. It is Rare and Threatened.

Astragalus barrii

Barr's Milkvetch

Centered in the Powder River Basin of northeastern Wyoming (Campbell, Johnson, Natron, Niobrara, Sheridan and Weston counties) and adjacent southeastern Montana (Big Horn, Carter, Powder River and Rosebud counties), to southwestern South Dakota (click here) (Fall River, Shannon and Pennington counties) and northwestern Nebraska (Dawes County).

Number Left 

Montana: 33 occurrences (Fertig 2000).
 
Nebraska: 1 occurrence (Weedon 2001).
 
South Dakota: 7 occurrences (Ode 1988).
 
Wyoming: 26 occurrences (Hartman and Nelson 1995)