I see my grandmother in the several postures that were peculiar to her: standing at the wood stove on a winter morning . . . sitting at the south window, bent above her beadwork . . . going out upon a cane, very slowly as she did when the weight of age came upon her; praying. I remember her most often at prayer.

When Momaday remembers his grandmother "most often at prayer," she is praying to Tai-me, the Sun Dance god. This, of course, is a very important connection to Momaday's Kiowa heritage. Later in The Way to Rainy Mountain, the reader learns that Momaday's grandmother was present at many important Kiowa events, including the last complete Sun Dance where the religious rituals to Tai-me were completed. She was also there for the last incomplete Sun Dance when the Fort Sill soldiers arrived and dispersed the Kiowa tribe. 

Just like the quotation above mentions, Momaday has many memories of his grandmother, Aho, at prayer to Tai-me.  Aho's prayers were often rambling, long, and anguished.  Her prayers are representative of her grief for the dispersal of the Kiowa tribe members. Momaday is able to explore his heritage fully because of the good relationship he had with his grandmother, Aho.