Before European colonization, Native American bands along the southern Texas and northern Mexican gulf coast were hunter-gatherers. In this vicinity, beginning in 1973, archeologists excavated Native American burial grounds in two separate soil strata. The older graves date to the middle archaic period, around 850 B.C., and the upper level dates to the late archaic, around 250 B.C. Artifacts show that the hunting-gathering culture endured across both periods, relying on spears tipped with dart points to hunt large game such as deer and bison. About 200 graves contained personal possessions including tools for sewing and cooking, shell ornaments, and red and yellow pigment and ocher stains. A few graves containing the remains of adult males had white-tailed deer antler racks affixed to them, indicating that those individuals held high social status. Trade items such as projectile points and shell beads indicate exchange of goods with coastal and interior groups. Forensic evidence suggests that only thirteen males and four females may have lived past the age of forty. Scientists and scholars from several universities assisted the Texas Department of Transportation in the Loma Sandia Excavation Project.