The activation of spallation targets of Pb and W has been studied for range-thick targets at proton energies of 0.84, 1.00, and 1.42 GeV. The production of radioactive nuclei per incident proton per cubic centimetre has been determined at six depths in the target material. Comparisons have been made with high-energy transport code calculations at 0.84 and 1.00 GeV and with calculations for 800-MeV experiments using similar targets at Los Alamos National Laboratory.