This report describes recent low-intensity archaeological investigations conducted at three small sites in the northern Basin of Mexico. The sites are represented by surface artifact scatters and are located on the former shoreline of the now-drained Lake Xaltocan, originally one of the principal lakes in this region. Fieldwork included mapping surface concentrations and site dimensions, conducting test excavations, and recovering surface collections. The analysis of surface artifacts focused on determining site function and chronology. Based on fieldwork and analysis, we propose that Michpilco likely was a habitation site with a substantial occupation during the Classic period. The smaller Non-Grid 5 site was occupied during the Epiclassic period, and site Non-Grid 6 was occupied during the Late Postclassic to colonial periods. These sites reflect occupations in a lacustrine landscape throughout different periods. They also exemplify the rapid disappearance and threat of destruction that looting, infrastructural development, and agriculture pose to archaeological sites in the region.