Deergrass was very important in the lives of Cahuilla people because of its use as foundation bundles in baskets. It was also used for the foundation in Kumeyaay baskets. The following information about Cahuilla basketry is from Dr. Deborah Dozier of the Palomar College American Indian Studies Department: The patterned surfaces are all made by wrapping a foundation bundle of cleaned and sized deergrass stems in paper thin strips of basket sumac (Rhus trilobata) and more typically basket rush (Juncus textilis). The sumac is left untreated and is valued for its pure white color. Juncus is valued for the distal end that is buried in the soil and turns a mahogany red, as well as the golden tan color that most of the rush takes when properly dried. Sometimes the Juncus is dyed black using the leaves of elderberry (Sambucus mexicana) mixed with emptied hulls of acorns, mostly black oak (Quercus kelloggii). When the basket is finished, no trace of the deergrass foundation is visible.

To create a basket 14 inches in diameter and 4 inches deep takes about 1,500 stalks (culms) of deergrass. The pattern of the stitching in a top-notch basket is remarkable in that it expresses the same Fibonacci patterns as pineapples, pine cones, and other arrangements of rotational geometry. It is amazing that these women did this at 40+ stitches per inch without any pattern to follow. For more information see Temalpakh: Cahuilla Indian Knowledge and Usage of Plants by Lowell John Bean and Katherine Siva Saubel (1972).

Primary coil is more accurately referred to as the foundation.

General structure of a coiled basket. Bundles of flowering stems (culms) of deergrass (Muhlenbergia rigens) were commonly used by the Cahuilla, Kumeyaay and other tribes for the foundation (primary coils) of the basket, around which the secondary coils were tightly wrapped. Basketbush (Rhus trilobata) was commonly used for the secondary coils, with intricate designs made from brown coils of rush culms (including Juncus acutus, J. effusus, J. lesueurii and J. textilis). Sometimes the rush culms were dyed to produce various color patterns. Other plants were also used for basketry in the American southwest, including willow (Salix), beargrass (Nolina microcarpa), yucca (Yucca elata) and devil's claws Proboscidea parviflora ssp. parviflora var. hohokamiana.

One of the most conspicuous plants of southern California is deergrass (Muhlenbergia rigens), a tall, perennial bunchgrass. It forms dense clumps up to four feet tall in mountain meadows, including the nearby San Jacinto and Santa Rosa Mountains. It also grows in moist canyons on the coastal and desert sides of the mountains, including Palm Canyon and Borrego Palm Canyon (Anza-Borrego Desert State Park).