Conserving the Nature of America
Service Completes Initial Reviews on Endangered Species Act Petitions for Three Species

March 23, 2021


Brian Hires,, 703-358-2191

The U.S. Fish and Wildlife Service has completed initial reviews on petitions to list three species under the Endangered Species Act (ESA), the Rio Grande shiner, Shasta snow-wreath and threecorner milkvetch. After reviewing the information in the petitions for each of these species, the Service has found that there is substantial information that listing under the ESA may be warranted.

The Rio Grande shiner, a small freshwater fish, was believed to occur from the Rio Grande and Pecos river headwaters in northern New Mexico, downstream through Texas, along multiple Rio Grande tributaries in Mexico. It has been extirpated from much of its historical range, and in New Mexico, is only known to occur in the Pecos River in Eddy, Chaves and De Baca counties. In Texas, the species has been lost from nearly its entire historical range except for a few individuals collected from the Rio Grande in Maverick County. Major threats to the shiner include reduced stream flow, hydrological alterations such as dam impoundments and declining water quality. The Rio Grande shiner was added to the Texas Parks and Wildlife Department list of state threatened species in early 2020.

The threecorner milkvetch, is a slender annual plant in the pea family that grows in sandy soils in the Mojave Desert in Nevada and neighboring Arizona. Given its narrow distribution and small population size, it is especially vulnerable to threats, which include habitat loss due to development, invasive plants, utility corridors, off-highway vehicle use and cattle grazing.

The Shasta snow-wreath is a deciduous shrub reaching up to eight feet in height and is found only around the perimeter of Shasta Lake in western Shasta County in northern California. It is a rare species of shrub in the rose family, and was not known to science until 1992, when it was discovered east of Redding, California. The inadequacy of existing regulatory mechanisms are one of the potential threats to the snow-wreath.

The Federal Register docket numbers and links for the substantial petition findings in this batch are:



Docket Number

Docket link

Rio Grande shiner

NM, TX, Mexico


Shasta snow-wreath



Threecorner milkvetch




The notice for the above findings will be available in the Federal Register Reading Room on March 23, 2021 at on the 2021 notices link under Endangered and Threatened Wildlife and Plants.

For more information on the ESA listing process, including 90-day findings and status reviews, please go to

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