Leslie Canyon National Wildlife Refuge in Arizona was established in 1988 to protect habitat for the endangered Yaqui chub and Yaqui topminnow and to preserve a rare velvet ash, cottonwood, and black walnut gallery forest. In the San Bernardino Valley’s basin and range landscape, relatively recent volcanic activity and earthquakes created plugs, cones, springs, and seeps that helped store water and support unusually rich plant and animal life. Although the valley once held creeks, wetlands, and giant sacaton grassland, late nineteenth-century settlement, farming, mining, and livestock use depleted limited water supplies, lowered the water table, and destroyed much native aquatic habitat.