Some preliminary findings of the Sulfate Regional Experiment (SURE), sponsored by the Electric Power Research Institute, are summarized. The design and implementation of ground-station and aircraft observations are briefly described, and some observations made during quarterly intensive sampling months are presented. The results obtained to date indicate that: (1) high-volume suspended particulate matter (TSP), SO/sub 2/, and NO/sub 3/ maxima tended to be localized on scales of about 100 km on an annual average basis, (2) TSP tended to be highest near source areas, the highest annual rural SO/sub 2/ concentrations occurred along the Ohio River Valley, and the highest annual rural NO/sub 3/ concentrations occurred in the vicinity of urban areas, (3) nitric acid may be an important component of the total atmospheric NO/sub 3/, (4) SO/sub 4/ appeared to be regionally distributed, and the SO/sub 4/ concentrations were relatively uniform from the ground to 1.5 km above m.s.l., (5) about 75 to 95% of the total SO/sub 4/ occurred in small particles, and (6) the zones of maximum sulfate dosage tend to shift from the northeast during the summer months to the southeast during the fall and winter months.