You're talking about this place ? :
HCCP - Home Page
If so, you'll notice it's on BLM land. So as such, there is no prohibition on metal detecting. In fact, there's an express ALLOWANCE of md'ing on BLM land
Metal Detecting, Bureau of Land Management, California
However, notice that it's ok, as long as you don't remove "artifacts". But notice it doesn't define "artifact". I suppose if you wanted to assemble a team of lawyers and purist archies, you can probably find someone to tell you that means an object over 50 yrs. old. Hmm, in my nearly 40 yrs. of this, I have YET to have anyone follow me around with a calculator, doing the math on the ages of coins I find. Nor is my math that good anyhow
And I also don't know about any particular "ghost town" site within that location. If you say there was a town there at one time, are foundations or something still showing? Or is the spot marked in some way? (historical plaque or something?) Or is this un-marked, and un-known, unless you were to research out exact spots of structures ? Either ways: just be aware of a psychological rule:
While detecting may be allowed someplace, it's generally a good idea to avoid being a nuisance around "obvious sensitive monuments". I mean for example: if there were an archaeologist convention going on at that spot, at the exact moment you got there, then .... well .... probably not a good idea to go flaunting your legal-ness. Pick discreet lower-traffic times. And then yes: If some busy-body
were to approach you, you *do* have the law on your side. Because you're only finding new stuff afterall,
*right* ?