Excerpts from the report: The Umatilla Drainage Basin in northeastern Oregon includes the watersheds of the Walla Walla River, the Umatilla River, and Willow Creek. It is bounded by the Grande Ronde Basin on the east, the John Day Basin on the south and west, and the Columbia River and Oregon-Washington state line on the north. The basin has a total area of about 4,554 square miles, which is 4.7 percent of the total area of Oregon. It includes most of Umatilla and Morrow Counties and minor portions of Gilliam, Union, and Wallowa Counties. For the purpose of this report, the Umatilla Drainage Basin is divided into three subbasins. Subbasin 1, the Walla Walla Subbasin, has an area of 486 square miles and includes the Walla Walla River and its tributaries in Oregon. Subbasin 2, the Umatilla Subbasin, has an area of 2,666 square miles and includes Juniper Canyon and all the drainage area of the Umatilla River. Subbasin 3, the Willow Subbasin, has an area of 1,402 square miles and includes the Willow Creek drainage and some smaller tributaries of the Columbia River between Willow Creek and the Umatilla River. Forty- eight percent of the basin is range; 36 percent is cultivated; 14 percent is forest; and 2 percent is devoted to other uses. Eighty-five percent of the basin is privately owned. This report presents information concerning the water and related land resources of the Umatilla Drainage Basin, the result of a cooperative study by the U. S. Department of Agriculture and the State Water Resources Board of Oregon. The objectives of the cooperative survey were to gather basic data and information pertinent to the use and control of water for agriculture in the area, to highlight such major water related problems as erosion, flood prevention, and drainage, and to outline a general program for water and related land resource management to be used as a background for future detailed study and planning.