Astragalus altus
Worthington, Richard D. 2003. Botanical surveys 2003 field season. Wildland urban interface fuel reduction project Lincoln National Forest, Nelson Unit. Southwestern Research and Professional Services, El Paso, Texas. 3 p +120 p field notes.
United States Forest Service. 2002. Environmental assessment: Rio Penasco II.. United States Department of Agriculture.. 200 p.
United States Forest Service. 1987. Astragalus altus monitoring plot with specimen locations. United States Forest Service (USFS) Regional Office, Albuquerque, NM. p.3.
Southwestern Field Biologists. 1996. Cloudcroft area plant survey. P.O. 43-7512-6-0081. December 16, 1996. Prepared for Lincoln National Forest.
Lee-Chadde, S. and L.F. Huenneke. 1997. A handbook of rare, threatened and endangered plant species of the Sacramento Mountains. Dept. of Biology, New Mexico State University, Las Cruces, NM 88003. Draft. pp. 109.