correlated to fluctuations of Lake Estancia; they suggest that Lake Estancia may have desiccated 134,000–121,000 years ago. Between 69,000 and 19,000 years ago, water levels were higher 41,000–38,000 years ago and lower 57,000–51,000 and 45,000–43,000 years ago, consistent with climate patterns recorded in regional cave deposits. The low water level stages correlate to the timing of maximum summer insolation and warm periods in Greenland; however, problems with dating these fluctuations make any inference about correlations to events elsewhere in North America problematic. Last Glacial Maximum and later The lake sediment record indicates that shallow lakes re-formed between 45,000 and 40,000 years ago. Water levels began to rise 24,000 years ago, and at least five highstands occurred during the LGM, with two more before and after the LGM. At least ten separate oscillations in water levels took place. Radiocarbon dating has yielded ages of 24,300 years ago for the first freshwater stage and 20,040 for the gap between the second and third freshwater stage. The expansion of lakes during the LGM was triggered by the growth of the Laurentide Ice Sheet, which forced the jet stream southward. A highstand around 23,000 years ago appears to coincide with Heinrich event 2, an episode in the North Atlantic where ice discharge into the ocean was increased and impeded heat transport by ocean currents. The highstands lasted until 18,100–17,000 years ago when water levels declined, an event christened the "Big Dry" in the Lake Estancia basin. This dry interval separates the LGM highstand from the following highstands, and correlates to an episode of strong East Asian Monsoons. Evidence of the "Big Dry" has also been identified in South America, where the drying of paleolake Sajsi in the Altiplano of Bolivia may correlate to the Lake Estancia event, but not elsewhere in the Great Basin. It appears that during the "Big Dry" climate patterns in New Mexico decoupled from climate variations elsewhere on the world. Both its beginning and its end have been correlated to ice-rafting events in the North Atlantic but it is not clear how ice-rafting events could simultaneously trigger the beginning and the end of a dry episode. Possibly, the southward migration of the Intertropical Convergence Zone during the "Big Dry" cooled the northeastern Pacific, inducing drought despite the occurrence of a more winter-like atmospheric circulation over North America, which would be expected to increase precipitation. Later research has proposed that the