[en] The results and description of hydrologic testing activities for the Rocky Coulee flow interior at borehole DC-4, over the depth interval 2894 to 2942 ft, are presented in this report. Hydrologic tests, including an over-pressure pulse test and a constant head injection test, were conducted during April and May 1983. Results from hydrologic tests performed indicate transmissivity values ranging from 7.9 x 10^-7 to 1.7 x 10^-6 ft²/day. The best estimate of equivalent hydraulic conductivity, based on an effective test interval thickness of 48 ft, is 2.5 x 10^-8 ft/day. Best estimate values obtained from testing fall within the lower range of hydraulic properties previously reported for similar Grande Ronde Basalt horizons. 16 refs., 8 figs., 4 tabs