During the geomagnetic storm of March 16--17, 1976, observations were made of precipitating protons, alpha particles, and heavy ions by two counter telescopes aboard the low-altitude S3-2 satellite. These observations are presented in this paper and their significance discussed. Briefly, a two-zone precipitation region is observed on the nightside, at L?2.7 and L?4.0 with an &agr;/&rgr; ratio ~8¿10-3 in the low-latitude region and ~9¿10-4 at higher latitude at 0.4 MeV/nucleon. The heavier ions, CNO nuclei, are seen in the low-latitude zone with a CNO/&agr; ratio of ~5.6¿10-2 at 0.25 MeV/nucleon.