Energetic atomic (O+1 and N+1) and molecular (O2+1, No+1N21) ions of ionospheric origin were observed in Earth's magnetotail at X~-146 RE during two plasma sheet sunward/tailward flow-reversal events measured by instruments on the GEOTAIL spacecraft. These events were associated with concurrent ground-measured geomagnetic disturbance intensification at auroral- and mid-latitudes (Kp=7-). Engergetic ions in the sunward-component and tailward flows were from both the solar wind and ionosphere. Plasma and energetic ions participated in the flows. During tailward flow, ionospheric origin ion abundance ratios at -200--900 km/s in the rest frame were N+1/O+1=-~25--30% and (O2+1, NO+1, and N2+1)=~1-2%. We argue that tailward flow most likely initiated ~80--100 RE tailward of Earth and molecular ions were in the plasma sheet prior to geomagnetic intensification onset. ¿ American Geophysical Union 1994