Date of this Version
A 2460-year-long hydroclimatic record for Crevice Lake, Yellowstone National Park, Montana was constructed from the δ18O values of endogenic carbonates. The δ18O record is compared to the Palmer Hydrologic Drought Index (PHDI) and Pacific Decadal Oscillation (PDO) indices, as well as inferred discharge of the Yellowstone River. During the last century, high δ18O values coincide with drought conditions and the warm phase of the PDO index. Low δ18O values coincide with wet years and a negative PDO index. Comparison of tree-ring inferred discharge of the Yellowstone River with the δ18O record over the last 300 years indicates that periods of high discharge (i.e., wet winters with significant snow pack) correspond with low δ18O values. Extrapolating this relationship we infer wet winters and high river discharge for the periods of 1090–1030, 970–870, 670–620, and 500–430 cal years BP. The wet intervals at 670 and 500 cal BP are synchronous with similar events in Banff, Canada and Walker Lake, Nevada. The wet intervals at 970 and 670 cal BP overlap with wet intervals at Walker Lake and major drought events identified in the western Great Basin. These results suggest that the northern border of Yellowstone National Park straddles the boundary between Northern Rocky Mountains and Great Basin climate regimes.