Woodchucks (Marmota monax) were fed crown vetch (Coronilla varia) growing along a major highway that was harvested in 1979, before unleaded gas was widely used, and again in 1985. Crown vetch, harvested 300 m from the nearest road, was fed as the control. The crops were fed as 50% dry weight of the diet for 58 d. The concentrations of lead in the control, 1979 crop, and 1985 crop were, respectively, 0.74, 50.65, and 6. 78 ppm dry weight. The average ± SE) concentrations (ppm, dry weight) of lead found in the tissues of the control, 1979, and 1985 dietary‐treatment animals were, respectively, kidney, 0.36 ± 0.05, 5.78 ± 0.72, and 0.79 ± 0.09; liver, 0.09 ± 0.01, 4.71 ± 0.17, and 0.46 ± 0.06; muscle, 0.07 ± 0.01, 0.14 ± 0.02, and 0.07 ± 0.00; blood, 0.09 ± 0.02, 2.17 ± 0.13, and 0.31 ± 0.05; and bone, 1.27 ± 0.25, 47.52 ± 7.05, and 3.71 ± 0.65. No significant differences (p > 0.05) between dietary treatments were found in the general hematological analyses of the woodchucks. The ecological significance of these findings is discussed.