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. We selected two small watersheds in. Arizona and two in New Mexico. In each state one is in the black grama association, where rainfall is between 8 and 13 inches, and one in the blue grama association with pre~ cipitation up to 16 or 18 inches. These are the intermediate zones in which watershed erosion is most active and where soil and watel;' conser- vation is most needed. They are typical of most southwestern water- sheds, for which there is little information on vegetal cover and water yield, Not much can be gained by studying large areas where annual rainfall is below eight inches ,because we can't expect much, if any, improvement in vegetation under those conditions. The two watersheds in Arizona, within the Colorado River Basin, are Walnut Gulch at Tombstone--57 square miles, and the part of Lonesome Valley which drains into Verde River, near Prescott--84 square miles. Rain and stream gages are being installed in Walnut Gulch, and one large and several small control structures. Owners of watershed lands have agreed to cooperate. Professional research personnel assigned by the Soil Conservation Service include a hydrologist, a plant ecologist. a soils scientist and an engineer. .. , The plan is to record, during a 5-year calibration period, informa- tion on precipitation, water and sediment yields, vegetation, ground water storag'e, soil moisture, and use of the area by livestock. After present relaticlnships are recorded, a practical plan of improvement will be worke4. out jointly by the research staff, ranchers, and in New Mexico with the local soil conservation district. Arizona law limits jurisdiction of soil conservation districts to farm land. The plans, similar to those being qarried out by soil conservation districts, will represent what can be really expected over southwestern ranges, rather than the ideal. They will consist of good grass management, and range reseeding and small erosion control structures where practical. Relationships during and after the making of these improvements will be compared with those under present conditions. " A good start has been made on obtaining data which we hope will be satisfactory to all on what actually happens to water and sediment yields ~hen semi-arid ranges are improved in a practical manner. Unfortunately, research funds in hand and in prospect do not permit the project to go ahead as fast as it should. Partial completion of instrument installations in Walnut Gulch is all we can accomplish in fiscal 1954. Studies of existing conditions will be made in the other water- sheds, but installation of instruments must await 1955 funds. However, the argument has been going on for years and probably will continue until actual records are made. It is better to make a start and proceed as fast as we can than not to start. In the current reorganization of the Department, thh research is being transferred to the new Agricultural Research Service. We hope this organization will not allow any let-up in this search for answer s to questions in which we are all interested. . * * * * * * * * * ., -11-