Energetic ion mass spectrometer data obtained on ISEE 1 have shown that the plasma in the subsolar magnetospheric boundary layer, magnetopause, and adjacent magnetosheath have an ionospheric component (He+ and O+) in addition to the solar wind component (H+ and He++). We have examined in detail nine intervals where the location of the subsolar magnetopause and boundary layer are well defined by the ISEE 1 fast plasma and magnetic field measurements. In five of the identified boundary layer intervals, keV He+ ions were observed; energetic O+ ions were seen, above background, in two of the boundary layers where He+ was observed. The temporal resolution of the ion mass spectrometer was too coarse to rule out the possibility of He+ or O+ ions being present in the four remaining intervals. Ionospheric He+ ions were also observed in the magnetosheath in two (and O+ in one) of the nine intervals studied.