Do you think Forrest would have done recon missions?
He has said that when he came up with the hiding-a-treasure idea, "I decided, I knew where I was going to hide the treasure chest." Then, later in the Moby Dickens talk, he added, "that treasure chest, I've said, is in a very special place to me, and if I get another disease…"
So, these thoughts of knowing "where" and that it was very special to him would have been 15 years before he actually hid it. Before he would put pen to paper, he would need to look the area over, make sure it was still special to him, get his bearings anew on what could be used as clues, what stood out, to enable him to craft a careful poem. These features of the area would have to be near-timeless. No rockslides, forest fires, floods, land development easements, could ruin his eventual poem clues.
Although the poem is supposedly complete enough to take you to the treasure chest, it would seem reasonable that he would drive and hike to the location he intended to place it, and make sure that the lay of the land was as he remembered it. He would have to feel confident that he could get himself to the location, at his age, be able to navigate the terrain, get a feel for how "alone in there" the location was just so that there would be no unexpected surprises at the last second. If you're going into a place that is "no place for the meek," then you don't want to risk finding someone there who would be "brave," just by coincidence.
What I'm getting at is the logistics of placing the treasure have to be reasonable to him. Since the placing of the treasure and chest was done in two trips, in one afternoon, the first trip would be the treasure because he wouldn't want to leave the gold in his car unattended. But more than this, the "where" location has to be such that when he leaves it there to go get the chest, he doesn't want to come back and find the treasure gone. So, everything has to be carefully considered by him, hence recon missions. Also, the outcome cannot be that after he drops the gold off, when he then gets to his car he is too weak to make the second trip. He doesn't want to check into a hotel overnight because that is a possible giveaway to a few at the hotel when he announces the treasure hunt. (Unless he would pay in cash and use a false name when signing in. Hotels might look at you suspiciously if you don't offer a credit card when checking in.)
YNP would be difficult in logistics in this regard, since he was then living in Santa Fe, and it would not lend itself easily to recon missions. And he doesn't want to come across a wild animal with a knapsack of gold, or a person who might want to strike up a conversation, considering the crowds that flock there.
The thought of a rental car does enter into the picture, however, when he avoids answering the question of his age when he actually hid the treasure. Two years, when he was 79 or 80, so that no one could investigate when he may have rented a car if placed up in YNP.
But still, logistics dictate that he would like to do a practice run or two, to help him decide what the "blaze" would be when he would enter that into his poem. When he decided on the wording of "blaze," if it is an actual "something" at the site, then he must convince himself that it would still be around next weekend, 100 years, or 1000 years later.
Necessary logistics, with all of this in mind, place it in New Mexico or Colorado. Otherwise, he's bitten off more than he can chew.
When the big day would come for hiding his treasure, just for Southern Colorado, he would need to rise at 4:00am, say he's going fishing to his family the night before, then shower, breakfast, and head on out. He could get up to Southern Colorado by noon, and he would be "tired." Then, after placing it in a place he had decided upon, he could then get well out of the area, and if he needed a hotel for the night, he would be sufficiently far away to not worry about hotel records, or credit card receipts. A long day like that, and he'd be "weak" when he went to sleep for the night.
I'm still wondering what would be a very special place to him? Hope that can be derived from the book, since the poem makes no reference to what would be very special.