Long-term records of cyclic droughts are valuable for understanding future changes in hydrologic patterns and constraining climate models. A 3,300-year long record of δ¹⁸O and δ¹³C values from endogenic carbonate from Foy Lake, Montana is used to infer such droughts during the early Holocene. From 10.8 to 9.6 kyr BP, δ¹⁸O and δ¹³C values are low, indicating a period dominated by a cooler, less evaporative climate. Both records exhibit strong cyclicity in the ~200 yr range, which is inferred to be a solar cycle. A dramatic shift towards a warmer, drier climate occurs after 9.6 kyr BP in a step pattern, dramatic in the δ¹³C record. Warming occurs after the transition. Stochastic cyclicity dominates with weaker, but statistically significant, periodicities ranging from 40-70 yrs. These are believed to be an expression of the Atlantic Multidecadal Oscillation. This larger synoptic climate signal may be important to the overall Pacific Northwest climate.