I have been to the Buttes several times,I have dug for glass and I have surface collected also,I have turned out many nice points from surface collected glass,don't know why guys frown on it,some of it will be fractured or bubbly,I knock off a flake look at it ,if I don't like it ,I leave it there,You will pick up more good surface glass than you want to carry. Just 2-cents ' Frank