The world that the White Sands people inhabited was different from today’s New Mexico in almost every measurable dimension.

The climate was cooler — estimates vary by region and time period, but temperatures in the American Southwest during the Last Glacial Maximum were perhaps 10 to 15 degrees Fahrenheit cooler than the modern average, with some estimates higher in some seasons.

This cooler regime, combined with changed atmospheric circulation patterns driven by the ice sheets, produced significantly higher precipitation in what is now the arid Southwest.

The evidence for this is abundant: ancient lake levels, pollen records from lake sediments, the geochemistry of cave formations called speleothems, and the distribution of plant species whose modern ranges are limited to cooler or wetter areas than the LGM Southwest.

Lake Otero, at its maximum, may have been one of the largest lakes in the Tularosa Basin during this period.

The exact extent of the lake during the human occupation represented by the footprints is not fully resolved — lake levels fluctuated over time, and the footprint horizons represent specific moments in a long and variable hydrological history.