Donald W. Brown was instrumental in the establishment, in 1971, of the very successful  Hot Dry Rock (HDR) Geothermal Energy Program at the Los Alamos National Laboratory  in New Mexico. He directed the early geological and geophysical reconnaissance work  in the Jemez Mountains, directed the drilling and testing program in the first deep exploratory  well, and in late 1973 selected Fenton Hill (36 km west of Los Alamos) as the Laboratory's  HDR Test Site. Don was the HDR Project Manager through the difficult period from 1983 to  1985, when the deeper (4000-m) reservoir at Fenton Hill was first created by hydraulic  stimulation and then tested as a closed-loop circulating system. He subsequently served  as the lead reservoir engineer for the HDR Project from 1992 through 1995, a time that covers  the successful flow testing of the deeper HDR reservoir at Fenton Hill.