Benito Range region has great variety of stuff, from chromium and nickel ultramafics to Great Valley inland sea fossils. Consult a Calif. geology map, a road map, and knock yourself out! And, as with all rockhounding, before your feet hit the ground, ask yourself the following question: "Will the next ten steps put me at serious risk for acute lead poisoning?"
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I've been fortunate several times in my life to see things that few people even know exists. Rockhounding in the Mercy Springs area back in the 1980's, I noticed that there were areas of ephedra savanna, a vegetation formation I'd never seen described despite my extensive research on that subject.
When Dr Love of grassland science fame died, through sheer luck and evident passion for the subject I got to cherrypick from his library which was supposed to be offered for sale on an all or nothing basis. Provided that I kept my damn mouth shut until.... well....I guess... now. Even in his library, and until this day on Wiki, I have found no documentation of an ephedra savanna anywhere on the planet, much less in California. A few years later I returned to the area with camera hoping to document it and unfortunately "modern range science" had caught up. The ephedra trees were regarded as nuisance competitors for soil moisture otherwise available to grazeable grass, and had been chain bulldozed just like junipers in intermountain region juniper grassland/woodland. Is the species extinct? Was it ever even recorded scientifically? I don't know. All I know is that it was once there and last time I looked none were left standing. Yes, these are trees I'm talking about, not 1-meter-high shrubs, and they were good browse the evidence being the trunks were pruned bare by cow and sheep livestock. Chaining them did not improve the range, it degraded it.
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[EDIT] thanks to the varied geology of the region, it's also a great area to research the electromagnetic properties of soils. I still have in my "professional collection" many rock and soil samples from that area. It taught me a lot about the relationship between soil chemistry and soil magnetic properties, information that is to my knowledge not in print anywhere and which I use to this day in metal detector engineering.