00934cam a22002771 4500 gs 44000046 DLC 20260227111350.0 780808s1944 oruaf b s000 0 eng c gs 44000046 (OCoLC)4120272 U. S. Geol. Survey. Libr. NcRS NcRS OCoLC DLC x4x4 QE155 .A3 no. 26 QE571 .T85 631.45 Twenhofel, William H. (William Henry), 1875-1957. Soil, the most valuable mineral resource, its origin, destruction and preservation, by W. H. Twenhofel. [Portland, 1944] 45, [2] p. illus., plates. 28 cm. Oregon. State Dept. of Geology and Mineral Industries. Bulletin no. 26 Reproduced from type-written copy. "References cited": p. [46]-[47] Erosion. Soil conservation. 27959 27959