Montina is a type of flour created from milled Indian rice grass (Achnatherum hymenoides), a type of grass native to the Western United States. Indian rice grass was grown and used by Native Americans as much as 7,000 years ago. (The grass is not related to rice.) The flour is gluten-free. Montina was determined to be gluten-free by Dr. David Sands, a plant pathologist working at Montana State University.

Indian rice grass is now grown by local farmers and processed at individually owned and dedicated gluten-free plants. The majority of farms producing Montina in the United States use no GMOs in the growing of the rice grass or processing of Montina Flour.