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• •`J 74-Torriorthents-Haplargids complex, very stony. The soils in this complex are nearly level to strongly sloping and are on toe slopes and small fans and in narrow, winding valleys. They are forming in an accumu- lation of locally transported stony materials derived from a variety of rock. Slopes are 0 to 12 percent. Torriorthents make up about 55 percent of this com- plex and are lower on the toe slopes than Haplargids and are in the bottom of small drainageways. Haplargids make up about 40 percent. They are more sloping than Torriorthents and are on toe slopes and tans. Included with these soils in mapping are areas of Flu- vents, flooded, that make up 5 percent of this map unit. Torriorthents are deep and well drained. They have little or no profile development. The surface layer ranges from sandy loam to clay Loam and is very stony. The underlying layers are sandy loam, loam, or clay loam and have cobbles, stones, and boulders. Content of rock fragments in the profile exceeds 35 percent. Permeability of the Torriorthents is rapid to moderately slow. Available water capacity is moderate to low. Roots penetrate to a depth of 60 inches or more. Surface runoff is moderate. The stony surface layer helps to prevent erosion. Some areas are subject to rare flooding. Haplargids are deep and well drained. These soils are highly variable, and profile development is weak to mod- erate. In some areas a thin, dark colored surface layer is forming. The surface layer most commonly is loam or sandy loam and is very stony. The subsoil is loam, clay loam, or light clay and has cobbles and stones. Content of rock fragments exceeds 35 percent. Permeability of Haplargids is moderate to moderately slow. Available water capacity is moderate to low. Root- ing depth is 60 inches or more. Surface runoff is medium. The stony surface layer helps to prevent ero- sion. Some areas are subject to rare flooding. Because of surface stoniness and slope, these soils are unsuited to crops. Seedbed preparation and drilling of seed for pasture plantings on depleted native range or in cleared areas are generally not practical because of surface stoniness. A limited degree of success can be expected by broadcasting seed late in summer or early in fall. Siberian wheatgrass, western wheatgrass, Indian ricegrass, and crested wheatgrass are adapted species. Good pasture management must be practiced to protect the soils from erosion and to provide grazing for live- stock. These soils provide habitat for desert cottontail, mourning dove, and chukar. Water developments can be used to improve wildlife habitat. It these soils are used for urban development, the main limitations are stoniness and overtlow. These limita- tions can be overcome by the use of proper design and construction methods. This complex is in capability subclass Vlls, nonirrigat- ed. 75-Torriorthents-Rock outcrop, sandstone, com- plex. This broadly defined map unit consists of moder- ately steep to very steep soils and Rock outcrop on mountainsides and foot slopes. Torriorthents make up about 60 percent of the map unit, and sandstone rock outcrops make up about 30 percent (fig. 7). Slopes are 20 to 70 percent. Torriorthents most commonly occur in the less sloping areas and are lower on the foot slopes than the rock outcrops. The sandstone rock outcrops generally are steeper than the Torriorthents. Rock escarpments com- monly occur on the upper part of the slopes. Included with this complex in mapping are small areas of Kech and Progresso soils and Fluvents, flooded. Torriorthents are well drained. Depth to bedrock ranges from 10 to more than 60 inches. The deeper Torriorthents are near the bottom of the slope. The sur- face layer is generally loamy and is very stony, because rocks weathered from escarpments are carried downs- lope by gravity. The underlying layers are sandy loam or loam and have a high content of rock fragments. Stones that are many feet in diameter are common. Permeability of Torriorthents is moderate to rapid, and available water capacity is moderate to low. Depth to bedrock limits rooting depth, but tree roots commonly penetrate fractures in the rock. Surface runoff is rapid. Surface stoniness helps to prevent water erosion. Mass wasting is common in areas of this map unit. The Rock outcrop part of this complex consists of more than 90 percent exposed bedrock, principally sand- stone. It provides cover for wildlife and is used mainly for wildlife habitat and recreation. The soils in this complex have only limited value for grazing and are used mainly for wildlife habitat and rec- reation. Vegetative cover is needed to control runoff and erosion. This map unit provides cover and escape for wildlife. Deer commonly feed on the sunny slopes during winter. Because of surface stoniness and slope, the soils in this complex are unsuited to crops and seedbed prepa- ration and drilling of seed for pasture plantings on de- pleted native range or in cleared areas are generally not practical. A limited degree of success can be expected by broadcasting seed late in summer or early in fall. Siberian wheatgrass, western wheatgrass, Indian rice- grass, and crested wheatgrass are adapted species. Good pasture management must be practiced to protect the soil from erosion and to provide grazing for livestock. If this map unit is used for urban development, the main soil limitations are slope and stoniness. These limi- tations can be overcome by the use of proper design and construction methods. This complex is in capability subclass Vlls, nonirrigat- ed.