Ethnographic information on dietary plants can be cast into an ecological framework by using vegetation sampling techniques. Lists of ethnobotanical species become the basis of a dietary inventory that applies to a regional assemblage of vegetation types in a landscape associated with an archaeological site. But such lists are usually derived from many sources often without biogeographic or temporal reference. In effect, the dietary inventory represents potential food plants that may ultimately be found in archaeological deposits. The dietary palette, however, is composed of plant species that actually occur within the greater landscape of an archaeological site and that may or may not be known from the ethnographic record. Vegetation sampling provides a quantitative assessment of the dietary palette in the local ecosystem by using standard metrics, such as plant cover, basal area, density, and even productivity. By comparing vegetation data to the dietary inventory and archaeobotanical record, general patterns of foraging behavior as predicted by behavioral ecology are verified. This study of the Southern Paiute in south-central Utah also compares the plant species composition of modern and ancient landscapes, emphasizing a lack of correspondence between the dietary inventory and the dietary palette, as well as with the archaeobotanical record. Our example is from North Creek Shelter, a well-stratified archaeological site on the Colorado Plateau.