I did a little googling, and found an image of the North Half of the Inyo N.F. area, which covers the are you are going to. It shows "unimproved campgrounds" which I would imagine are just one step above "dispersed camping". The map doesn't identify anything representing dispersed camping in its key.
From:
Gentry Off Road -- link to
Inyo North Half Map.
Edit: Inyo staff contacted me and pointed out that the areas outlined in pink are areas where dispersed camping is prohibited.
For example: Near Crowley Lake, see the McGee Creek and Convict Lake roads. Also, a large area surrounding Mammoth Lakes is enclosed in the pink lines.
Also, the current map shown on the above link is currently being updated by Inyo, and is not yet available.
