Isn't it fun trying to figure out a gobbler? Just when you think you know what he's going to do...he does a "vanishing act".
Several years ago I hunted the Mark Twain National forest with an older turkey hunter. He had a theory about the "the bubble" as he called it. He said that if a turkey felt comfortable in an area (the bubble) he'd be much more willing to come back to it. Whenever a turkey did that "Houdini", he wait until he thought he was really out of the area and then move to the last place he saw him. He'd settle in and call on a regular basis. Many times, the old gobbler would make his way back to his "bubble" and he'd shoot him.
I've tried that over the years and many times with the same success. It doesn't work all the time of course but I've come to believe that it's better than tramping through the woods trying to locate another bird.
I think I'd go sit by that rock.
Good luck and let us know when you get him.
"If he's out of range, it just means that he has another day and so do you."