Arizona Game & Fish Dept plant abstracts, maps and illustrations

Arizona Rare Plant Field Guide

Center for Plant Conservation (National Collection of Imperiled Plants with range of Utah)

CNPS Rare Plant Program (California)

Colorado Natural Heritage Program

Colorado Rare Plant Field Guide

Colorado State University Herbarium - Rare plants of Colorado

Idaho Fish and Game Rare Plant Field Guide to the Pocatello and Idaho Falls Fields Offices, BLM

Intermountain Regional Herbarium Network

Montana Natural Heritage Program plant field guide

NatureServe

Navajo Natural Heritage Program (includes Navajo Endangered Species List, status, reports, abstracts, photos)

Nevada Rare Plants

New Mexico Rare Plants

NRCS Publications Relating to Threatened, Endangered, and Rare Plants

Oregon Rare Plant Guide

USDA Forest Service Celebrating Wildflowers: Rare Plants

USDA Forest Service Celebrating Wildflowers: Intermountain Region Rare Plant Profiles (critically imperiled plant profiles available as of July 2009)

USDI National Park Service Glen Canyon NRA Rare Plants

US Fish & Wildife Service Mountain Prairie Region

Utah Conservation Data Center (UDWFR)

Utah Division of Wildlife Resources Field Guide

Washington Natural Heritage Program Field Guide to Selected Rare Plants

Wyoming Rare Plant Field Guide