The mission land was divided into thirty-five land grants in San Luis Obispo county, three of which were located on Cal Poly land.

• Rancho San Luisito consisted of 4,389 acres, and was granted to Guadalupe Cantua in 1841.
• Rancho El Chorro (meaning "waterfall") consisted of 3,167 acres, and was granted to Captain John Wilson and his partner James Scott in 1845.
• Rancho Potrero de San Luis Obispo (meaning "pasture") had a more complicated history. Approximately 2,000 acres were originally acquired by Estevan Quintana in the late 1820's. However, a 3,506 acre parcel comprising the same land was later granted to Maria Concepcion Boronda in 1842. Eventually, Quintana was able to retain control of the land, later passing it on to his heirs.
  
  The rancho boundaries often relied on natural features, crude maps, and rough approximation. It is interesting to note that in some places Cal Poly’s boundaries still preserve similar irregular boundaries.