You don't need private land if you are willing to walk a lot. You can find areas where you can catch private herds moving onto public. It will not be close to the roads. It takes a lot of walking and map study, but it can be done. It is not a drive around till you see one area. I walked a total of 43.6 miles on my trip per onXmaps.
I found one thing very funny when I was out there. When driving around you almost did not need onXmaps. When you can see antelope from the road it will be private land. You can tell the minute you hit public land as the antelope are no where to be seen.
I think I saw a antelope buck looking at his phone on onXmaps to be sure he was on private land.