In the past, cattle production on Southwestern ranges has been a business with "ups and downs," with prosperity or adversity governed by climatic conditions, which brought seasons of plenty in range forage and stock water followed by seasons of restricted forage growth and scarcity of water. Soon after the cattle business became established on the open public range of the Southwest, the herds were built up during a period of good years until the developed ranges were stocked fully or beyond the number they could carry even in good years. Then, at intervals, came dry periods, series of dry years with much less forage produced than was required by the stock on the range and with heavy losses from starvation. During the early days, before all the ranges had been opened up, there was opportunity to develop new range during such emergencies and, thus, to relieve the situation to some extent. Such possibilities diminished more and more, however, as practically all the range came into use. During the drought that ended in 1910, there was little opportunity of this nature and practically none in the drought of 1916 to 1918. The setback to the livestock industry, caused by the combination of unfavorable climatic conditions and unwise range practice, comes about mainly through heavy losses of stock, low calf crop, interference with improvement of breeding herds, retarded growth of young stock and range deterioration. During the last drought (1916 to 1918), according to estimates based on the best data obtainable, losses were at an average rate of 20 per cent annually for the three-year period and reached as high as 35 per cent in 1918, the worst year of the drought. Individual losses were as high as 50 per cent. The large reduction in calf crop is probably next in importance to losses. Natural increase is the main source of income, and if greatly reduced at a time when expenses are high, the result is serious. The calf crop for some of the ranges affected by the last drought was estimated at 35 per cent in 1917, 25 per cent in 1918 and 35 per cent in 1919, the three years most influenced by the drought. These figures are probably not far from representing the true situation. Drought also has been a prime factor in retarding improvement in the grade of stock. Heavy losses and forced sales might wipe out years of effort in building up the herd or reduce the numbers to an extent that culling and selection necessary to maintain quality would not be consistent with the importance of increasing the herd to take advantage of good years; or, the set-back might be such that it left the stockman financially unable to purchase the right kind of bulls.