El Dorado County in CA, right? There's probably scores of stuff written about all the various CA indians over the years. No shortage of indian stuff written by archaeologists here. If you're having a hard time finding stuff about just that particular band or tribe, it could be because you're limiting your word searches too narrowly. Sometimes indian groupings had, or used, different names for themselves. Like here on the coast of CA for instance, there were sub-groups, with their own names, within a larger name that covered the entire central coast area, or whatever. So maybe there is stuff written about the indians in your area, but just not referring to them as "Maidu", and just going by a broader name for the entire Sierra foothills region.
The CA indians had no refined metals, so their sites, before the contact-period, would have nothing to find with metal detectors. Once the missions got started, and trading began, it was only a matter of 50 to 75-ish yrs, before they became totally assimilated into the culture, and their ancestral villages were abandoned, or gave way to modern cities, etc... Here on the coast, we've found some of the historic indian "rancheria" sites that gave up some early metal items, because apparently they were on trading routes, and had contact with the incoming Spanish.
There's a few gold rush country folk on the Kinzli California forum that might know more about your area. To get to the main page, you have to sign up, but it's easy. Just pick a password to log in.