00931cam a22002771 4500 gs 62000242 DLC 20260227111411.0 860128m19629999dcua 000 0 eng c gs 62000242 (OCoLC)13071316 U.S. Geol. Survey. Libr. TxHR OCoLC DLC premarc QE75 .C5 no. 460 A, etc. Leopold, Luna B. (Luna Bergere), 1915-2006. Conservation networks, by Luna B. Leopold. Washington, 1962- v. illus. 27 cm. Geological Survey (U.S.). Circular 460 A- pt.A. The man and the hill.--pt.B. A national network of hydrologic bench marks. Hydrology Research. Nature Effect of human beings on. Water conservation. Man and the hill. National network of hydrologic bench marks. 29640 29640