This data is also available as a Google Earth-parsable KML file: MRDS_Mines_LA,Ventura,Kern.kml.
Basic Info: This is a simple Google Maps powered front-end to data I received straight out of the USGS Mineral Resources Data System (MRDS). This map by default centers itself around the Frazier Mountain communities area, since that is the area I live in, but this map can display MRDS data from anywhere in Kern, Ventura, and Los Angeles county. The blue marker indicates the current center of the plotting, as is defined by the Epicenter Latitude and Longitude above. Plots will only be drawn if they fall within the number of degrees specified in the Plot Radius field above from the Epicenter as determined by the distance formula. If more than the maximum plots match the current Epicenter Radius and Epicenter, then the number of drawn sites turns red to indicate there is missing data. The red markers indicate mineral sites from the USGS MRDS. Clicking them yields a pop-up balloon with lots of juicy information.
Technical rambling: - Since the distance formula applies to linear 2D graphs, but latitude and longitude are not a linear graphing system, the use of it here produces a vertically-stretched elliptical circle around the epicenter. This is because I am too lazy to figure out the trigonometry to make it a perfect circle. The whole reason I supply an epicenter, and limit the number of plots that can be drawn at maximum is that attempting to make the Google Maps API draw thousands of plots will crash my browser, and probably yours too.. but try it if you don't believe me! By default I have the max plots set to a conservatively low number for people with less memory than I do, but I seem to be able to get away with doing 500 - 700 plots at once.
(Ugly) Source Code