right|thumb|150px|Trenor W. Park managed Fremont's Rancho Las Mariposas. On February 10, 1847, Frémont purchased a 70-square-mile parcel of land in the Sierra foothills through land speculator Thomas Larkin for $3,000 ($ in ). Known as Las Mariposas (Spanish for "The Butterflies"), an allusion to the great number of Monarch butterflies found there, the land had previously been owned by former California governor Juan Bautista Alvarado and his wife Martina Caston de Alvarado. Frémont had hoped that Las Mariposas was near San Francisco or Monterey, but was disappointed to learn that it was further inland, near Yosemite, on the Miwok Indians' hunting and gathering grounds.
right|thumb|150px|Trenor W. Park managed Fremont's Rancho Las Mariposas. On February 10, 1847, Frémont purchased a 70-square-mile parcel of land in the Sierra foothills through land speculator Thomas Larkin for $3,000 ($ in ). Known as Las Mariposas (Spanish for "The Butterflies"), an allusion to the great number of Monarch butterflies found there, the land had previously been owned by former California governor Juan Bautista Alvarado and his wife Martina Caston de Alvarado. Frémont had hoped that Las Mariposas was near San Francisco or Monterey, but was disappointed to learn that it was further inland, near Yosemite on the Miwok Indians' hunting and gathering grounds.