The Cishan people farmed broomcorn millet, a hardy grain suited to the dry, continental climate of northern China. Cultivation of this crop on the site has been dated to as early as 10,000 years ago, though some archaeologists have questioned these early dates due to sampling issues and lack of systematic surveying. What is less contested is the evidence for foxtail millet cultivation beginning around 8,700 years ago. These two grains became the dietary foundations of northern Chinese civilization, a parallel to the rice agriculture developing independently in the Yangtze River valley to the south. The distinction matters: millet and rice agriculture gave rise to different cultures, different cuisines, and possibly different language families.

The type site at Cishan covers approximately 80,000 square meters on a low elevation mesa. Houses were semi-subterranean and round, dug into the earth for insulation against the harsh winters and scorching summers of the North China Plain. The residents kept domesticated pigs, dogs, and chickens, with pigs providing the primary source of meat. They hunted deer and wild boar in the surrounding forests and foraged walnuts, hazelnuts, wild apricots, and pears. Carp and herring from the nearby river supplemented their diet, caught with fishing nets woven from hemp fibers. This was not a people on the edge of survival. Their diet was diverse, their technology purposeful.

Over 500 subterranean storage pits were discovered at the Cishan site, a number that speaks to both agricultural surplus and social organization. The largest pits reached five meters deep and could hold up to 1,000 kilograms of millet. Storing grain underground keeps it cool and dry, protecting it from the insects and humidity that would destroy it above ground. The sheer number of pits suggests a community that produced far more food than it consumed in any given season, a surplus that would have enabled population growth, craft specialization, and trade with neighboring groups. Among their artifacts are stone grinders, stone sickles with carefully serrated edges for efficient grain harvesting, and a variety of pottery forms including basins, pot supports, serving stands, and drinking cups.

The Cishan culture has been linked by linguistic researchers to the origin of the Sino-Tibetan language family, the second-largest language family in the world by number of speakers, encompassing Mandarin Chinese, Tibetan, Burmese, and hundreds of other languages. The hypothesis, supported by phylogenetic analysis of comparative linguistic data, places the ancestral homeland of these languages in the millet-farming communities of the Yellow River valley. If correct, the farmers who dug storage pits and wove fishing nets at Cishan were not just growing food. They were shaping the linguistic heritage of billions of people who would come after them, their words evolving and splitting over millennia as their descendants migrated across the continent.