The combined data from the ISEE 1 medium energy and plasma instruments on November 29, 1977, have identified the existence of surprising spectral structures in the trapped ion population at low equatorial altitudes, 2≲L≲4 and &agr;eq>50¿. By analyzing our instruments responses at the limites of their capabilities, we are able to resolve a double peak structure just below the instruments' energy overlap region (20--40 keV). Two narrow ((ΔE/E)~0.4) energy peaks are observed. We conclude that for this specific case the higher energy (HE) peak is composed of protons and that the lower energy (LE) peak is made up to singly ionized ions (H+, He+, O+). At L~3 the HE peak is located at ~17 keV and the LE peak at ~12 keV. The energy of the peaks increases as L decreased and the intensity of the peaks is ~2(10)5 ions/cm s sr keV. Data from the medium energy particles instrument, which responds to the higher energy portion of the observed peaks, have been surveyed through the period November 1977-September 1979. Orbit geometry and available data recordings allowed these ions to be observed only for the six-month period November 1977 through April 1978 and over the local time range ~0300--1500 hours LT. These characteristics plus charge exchange lifetimes pose severe boundary conditions on possible source and injection mechanisms. Of those considered, ion cyclotron acceleration of thermal ions in the presence of an anisotropic energetic population appears a likely source of these quasi-monoenergetic peaks. Additional peaks in the energetic ion spectra are observed at energies >40 keV. Some of this higher energy structure may be related to cross L diffusion of multi-component ion populations.