Burial on The Old Spanish Trail

[Fielding]

Family historical records indicate a family member traveling from Yerba Buena, later named San Francisco, enroute to the Salt Lake Valley with a lot of gold from Sutter's Mill, was last seen in a place called "Rock Valley", California.   This occurred in the year 1849.   He was never heard of again.   

My question is:  Does anyone know the location of "Rock Valley" on the Old Spanish Trail in California? 

[Samuel]

There were many burials along the Old Spanish Trail.   Somewhere I remember reading about a campsite on the trail which was called Rock Valley.   My memory tells me it was southeast of San Francisco, maybe a days travel from the city.   There were a number of burials there.   I don't see it on the map.   It's probably a sub division now.   The man who's burial you seek is probably under a high-rise building.