Well I think we came up with a solution to our issuer, which is with FF USGS and BLM sites and I suppose boondocking sites. We like to drop the RV at a safe spot after some very bad experiences with FS roads, and then take the truck and find a site. WE then go get the TT. We also scout out FF sites the same way.
So my idea is to set up our canopy tent and use it to mark the site as taken. Worked this morning, we found a spot at Carabella, on the Madison River and 15 miles from Gardiner-YNP, BLM designated camping site, set up the canopy, went back for the TT as as we were leaving passed another camper coming in looking for a site.
That is the second time that happened, we had a like experience at the FF USFS site at Jacob Lake. Got there early and paid for one of the three empty. We to get the RV and passed 3 others coming in. Bird, Worm, Early
Our other thought is to carry a traffic cone, collapsible if possible.
NOTE: 1) Carabella is back in operation after the flood despite the website calling it a fishing access site.
2) Canyon USFS site on US89 14 miles from Gardiner may have empty site early in the morning, it had 4 or 5 this morning on a Friday too..