I'll give that website an E for effort. Way too slow to be useful, or I caught it at a bad time.
This link will take you to Dugway on Skyvector: skyvector
Skyvector is a bit more useful since it has many of the bombing target ranges on it. Once you know the SUA nomenclature, you can get the exact
coordinates on the FAA website if you need more detail.
Actually, it is... R6402, 6406 & 6407 are all continuous, up to like FL580 or something... which includes the field. Pretty much the same as most of
the Nellis range.