This stream flows in an easterly course, and enters the Green 32 miles above the junction of that stream with the Grand. It has three principal branches--Ferron, Cottonwood, and Huntington Creeks--all rising in the Wasatch Plateau at an altitude of about 10,000 feet. These streams have a rapid fall in their upper courses, and leave the plateau through almost impassable cañons cut in its eastern wall overlooking Castle Valley. They flow across that at intervals of a few miles apart, and, then uniting, cut a deep, narrow cañon through the San Rafael Swell. Emerging from the swell, the river flows across a low, broken country until its junction with the Green. The largest body of arable land within the drainage basin of the San Rafael is in Castle Valley, a long, narrow depression lying between the eastern escarpment of the Wasatch Plateau and the San Rafael Swell. It is nearly 60 miles in length from north to south, and has an average elevation of 6,000 feet above the sea. Its southern end, as has been before mentioned, is drained by the tributaries of Curtis Creek, the central portion by the three streams forming the San Rafael, and the northern by Price River. No permanent settlements have been made in the valley, but it is much used as a winter herding ground for stock owned by the settlers in other portions of Utah. Lying near the branches of the San Rafael that cross it, and in such position that the water can be easily conducted over it, are 200 square miles of arable land, generally of good quality. East of the San Rafael Swell, and lying on both sides of the river, at an altitude of 4,000 feet, are 20 square miles of arable land, which could be easily irrigated. The river was carefully measured in July, 1876, and the volume of flow found to be 1,676 cubic feet per second. The three branches in Castle Valley were also measured, with results closely approximating the measurement of the united streams. These measurements were made at high water, though not when the streams were at their flood. As most of this volume is derived from the melting snow, which rarely disappears from the high plateau before the middle of July, the flow would be maintained with considerable steadiness during a large part of what would be the critical period in the irrigation of this valley. After the middle of July the decrease would be very rapid until September, and the lowest stage of water reached about the first of October, when the river would not flow probably more than 400 cubic feet. THE PRICE RIVER.