Hi MEA,
I think some persistent rec climbers do the research and make forestry contacts to locate the champ trees. I had assistance from forestry groups and associations myself, but I was and still am a practicing certified arborist with a name.

General locations- like what state park they are located in, can often disclose a location with field work.

I have had reports from the rec community that they found the champ tree and were just happy with discovering it, leaving their ropes behind. The thrill of the hunt was enough.

I personally find these trees imposing (west coast trees). High blind anchor points (TIP) don't thrill me anymore. My reluctance is possibly the function of my age, a return to rational thinking, or a great wife.