The record of carbon-13 (deltaC-13) variations in DH-11 vein calcite core from Devils Hole, Nevada, shows four prominent minima near glacial terminations (glacial-interglacial transitions) V to II. The deltaC-13 time series is inversely correlated with the DH-11 oxygen isotope ratio time series and leads it by as much as 7000 years. The deltaC-13 variations likely record fluctuations in the deltaC-13 of dissolved inorganic carbon of water recharging the aquifer. How such variations are transported 80 kilometers to Devils Hole without obliteration by water-rock reaction remains an enigma. The record may reflect (i) global variations in the deltaC-13 of atmospheric CO2 and, hence, the deltaC-13 of continental biomass or (ii) variations in extent and density of vegetation in the southern Great Basin. In the latter case, deltaC-13 minima at 414, 334, 246, and 133 thousand years ago mark times of maximum vegetation.