No where is ever dug out, you just have to work harder for less sometimes but it will be there somewhere [] . My very best bottle came from somewhere that was "all dug out" 20 years ago, I found mine last year [] .
Good luck.
Carbonado is very well dug, and has been for years. Where exactly have you been digging? The old road from Carbonado to Huckle-Chuck, that runs under the bridge and opposite the current road, has sites that hasn't been to picked over yet. You might have better luck around Fairfax, Huckle-Chuck, Spiketon, Burnette areas.
Around Black Diamond, Franklin, and Kummer there are also several great sites.