Felipe Arroyo de la Cuesta was a Spanish Franciscan missionary and linguist renowned for his contributions to the study of native languages in California. Born in Cubo de Bureba, Burgos, he arrived in Alta California in 1808, where he dedicated himself to the Mission San Juan Bautista for 25 years. During his time there, Arroyo de la Cuesta immersed himself in the local cultures and languages, producing significant works on the Costanoan, Mutsun, and Yokuts languages. His efforts were pivotal in documenting and preserving the linguistic heritage of the region, which was rapidly changing due to colonization and missionization. After transferring his responsibilities at San Juan Bautista to Zacatean Franciscans in 1833, Arroyo de la Cuesta continued his missionary work at several other missions, including San Luis Obispo and Santa Inés, until his death in 1842. His legacy lies not only in his linguistic studies but also in his role as a cultural intermediary during a transformative period in California's history. Arroyo de la Cuesta's work remains a valuable resource for understanding the indigenous languages and cultures of early 19th-century California, highlighting the complexities of colonial interactions and the importance of language preservation.