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Occurrence of ground water in the basalt__________ 2 Suggestions as to general specifications for test wells_ Tectonic deformation of the basalt________________ 3 Test operation of the wells ______________________ _ Tilting and warping_________________________ 3

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Two seismic cross sections were run with a refraction seismograph near Spokane,, Wash,., in Hay and June l?5l» One section trended northsouth across the Spokane River valley plain just east of the Idaho-Washington boundary! the other trended east-west across the strath just north of the Hillyard section of Spokane. Each section secured data that permitted the compilation of a graphic cross section showing the position of (1) the water table, (2) the base of the glacial and glaciofluviatile deposits, and (3) the generalized base of the Latah formation and associated deposits (which is the top of the consolidated bedrock). The data confirm the inference of Pardee and Bryan that the granitic bedrock lies at an altitude of about 1,000 feet beneath the valley plain near the State boundary. The base (a heretofore unlocated feature) of the glacial outwash deposits, the main aquifer of the area, was determined as an uneven plane at an altitude of 1,600 to 1,700 feet in the State* boundary district and at 1,700 feet in the Hillyard Trough district.

The Klamath River basin, including the adjacent Lost River basin, includes about 5, £00 square miles of plateaus, mountain-slopes and valley plains in south -central Oregon* The valley plains range in altitude from about 1*,100 feet in the south to more than U,J>00 feet at the northern end 5 the mountain and plateau lands rise to an average altitude of 6,000 feet at the drainage divide, some peaks rising above ; "*! 9,000 feet. The western quarter of the basin is on the eastern slope of the Cascade Range and the remainder consists of plateaus, mountains, and valleys of the basin-and -range type* The rocks of the Klamath River basin range in age from Recent to Me so zoic. At the southwest side of the basin in Oregon, pre-Tertiary raetaraorphic, igneous, and sedimentary rocks, which form extensive areas farther west, are overlain by sedimentary rocks of Eocene age and volcanic rocks of Eocene and Oligocene age. These early Tertiary rocks dip ''east toward the central part of the Klamath River basin, the complex "volcanic rocks of high Cascades" include three units: The lowest unit consists of a sequence of basaltic lava flows about 800 f eet thick; the medial unit is composed of volcanic-sedimentary and sedimentary rocks the Yonna formation-200 to 2,000 feet thick; the uppermost unit is a sequence of basaltic lava » ' . , , ' * " flows commonly about 200 feet thick. These rocks dip east from the Cascade Unpublished records subject to revision . ***. .' ' *' general, south of Mount Mc&oughlln, by -fee southeast-and south-sloping plateaus that comprise that part of the Central Cascade Mountains section (Fenneman) where the true crest of the Cascades is less definite* The drainage divide in the Cascade Mountains occurs at a common altitude of about 6, i>00 feet. with many eminences rising. abovo that -level, Mount

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