For the past two years surveys have been in progress on the mountain streams of the Southwest. These investigations included chemical analyses, quantitative counts of bottom food organisms, a study of the physical character of the streams, and studies of the fish such as species present, relative abundance, age, and growth rate. An intensive creel census has been undertaken in several streams. An intensive study is being made on two experimental streams, one of which has been improved to the practical limit and the other left in its original condition.