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o C~ and Holbrook wells are free~flowing. The Coconino formation, the only formation which yields water suitable for irrigation, varies in thickness from some l, lOO feet along the Mogollon Rim to 450 to 900 feet in the Joseph City ~ Holbrook area. It is recharged principally from rain and melting snow percolating into the extensively exposed areas at the higher elevations along the Mogollon Rim. Some other formations contain minor amounts of groundwater which is usually unsuited to irrigation. c: - c c 7. The Little Colorado River Basin, located in eastern Arizona and western New Mexico, is a part of the Colorado Plateau Province. The watershed above Joseph City is a plateau irregularly dissected by the river and its tributaries. Its vegetative types range from the open rolling grasslands of the Upper Sonoran Zone upward through pinon~ juniper woodland and yellow pine belts to dense stands of Douglas fir, white fir and Engelmann spruce at the highest mountain elevations. Areas to the east and north of the project are composed mainly of open rolling grasslands, some timber lands, and include typical badland areas of the Chinle, Moenkopi, and Mancos formations which are highly erodible and contain considerable quantities of salts. The Wingate, Navajo and Mesaverde formations included are lesser contributors of sediment. These areas are drained by Little Colorado River tributaries, the more important of which are Carrizo Creek, Zuni River, Puerco River, and Leroux Wash. All of these streams are ephemeral in character and flow largely in response to rainstorms. During floods they carry heavy sediment loads, occasionally over 20 percent of the streamflow, and their salt content is generally fairly high. The badland areas support little vegetation and contribute large quantities of fairly alkaline sediment to the streamflow. As these badlands are not sus- ceptible to practical methods of erosion control, and as the grasslands are generally overused to the extent that they also are heavy sediment contributors, the sediment load carried by the Little Colorado River is at present very heavy. Soil conservation practices now being initiated by Federal agencies will in time, however, reduce this sediment load in some measure. To the south of Joseph City lies an undulating plain with a northerly slope from the Mogollon Rim to the Little Colorado River. This area is drained by the headwaters of the Little Colorado River and Silver Creek. The latter rises in the Mogollon Plateau while the Little Colorado River heads to the southeast in the White Mountains, and both, originating in well maintained forest areas, are perennial streams and carry little sediment and salts. 8. The soils of the project area are mainly alluvial. They originated primarily from the Moenkopi formation which is composed of thin~bedded sandstone and shale, Chinle shales lying to the north~ east and east of the project have contributed fine material, carried as suspended sediments by the Little Colorado River and its tributaries. Both of these formations carry considerable quantities of alkali salts. Although the Coconino sandstome is exposed in places, it contributed little material to the soil body. Project soils vary in texture from heavy slowly permeable clay to sandy loams and loamy sands and usually contain a layer of clay in the profile. Having developed under dry climatic conditions, they are low in organic matter and deficient in nitrogen and available phosphorus, but contain appreciable quantities ~ ~ 3