Loach Minnow in Upper Blue River
Blue River is tributary to San Francisco River in the greater Gila River basin. Its headwaters are in the physiographic setting of the Colorado River Plateau. The watershed is approximately 1602 square kilometers (km2) and the river flows for approximately 85 km before flowing into San Francisco River. Blue River is divided into two Fifth Hydrologic Unit watersheds (1504000403 Upper Blue River and 1504000407 Lower Blue). Elevations range from 2865 m near the Mogollon Rim to 1177 m at its mouth. The river corridor varies from wide flood plains separated by narrow box canyons to wide and narrow sandy river bottoms to a relatively narrow canyon with towering canyon walls. Slumps and fault lines are visible in some areas.
Blue River contains one of the highest diversities of native fishes in Arizona. Among these, it contains federally endangered loach minnow (Tiaroga cobitis) and 106.5 km of the main stem Blue River and its tributaries are designated critical habitat (US Fish & Wildlife Service [USFWS] 2012). Several Forest Service sensitive species also are present including desert sucker (Pantosteus clarkii), Sonora sucker (Catostomus insignis), and longfin dace (Agosia chrysogaster). Speckled dace (Rhinichthys osculus), a non-sensitive native species also occurs in Blue River.