George Rock also known as George Roche and probably George La Roche
was born abt 1785 in Lower Canada and died after 1850
Bancroft says "Rock (Geo.), 1836, first appears at Sonoma as a witness against a horsethief. iv. 118; seems to have had a rancho near Sonoma, and in '37 was nominal grantee of S. Julian, Sta B., iii. 655-6, being in '37 grantee of Guenoc, Lake Co. iv. 671."
There is confusion on the date of the grant, as I also have
authorities who state that "On 8 May 1845 Rancho Guenoc 21,220.03 acres was granted to George Rock by Pio Pico(or 8 Aug 1845)."
First book of deeds and alcalda records, Sonoma County, California
13 Jan 1847 From Jacob P Lease to George Rock, witness Richard Fowler
This is the deed where George Rock, for $300 grants Rancho Guenoc to Jacob P Lease.
Bancroft goes on to say "According to the Lake Co. Hist., he lived at Guenoc from about '48, as agent for Jacob P. Leese. "
Lake county history says "In 1850 Roch built a log cabin in the area where the Stone House is now. In 1851 the cabin was abandoned"
Here is George Rock in the 1850:
1850 Census Sonoma Co, California
Enumerated Oct. 20, 1850 by L.B. Mizner, Asst. Marshal
Rock Geo. 65 M Farmer 2,000 Lower Canada
Jacob Leese evidently abandoned the claim, and on 18 Dec 1852, Rancho Guenoc was taken over by Captain Archibald A Ritchie and Paul S. Forbes