Climbing Huge Tree - Special Techniques?

Hello. I have some mountain property that is home to a huge, very old, deciduous tree. The tree is 25 ft in diameter at the base. I can't be sure of the species as it's difficult to distinguish the leaves from those of adjoining trees in the canopy from the ground, but judging from the bark and the overall shape, I think it is probably tulip, hickory or oak. There is a very large branch (I'm guessing 18-24 in. diameter, possibly larger) that juts out nearly parallel to the ground at about 30 ft. up the trunk. That is the only feature below the canopy. I want to see if it is feasible to build an observation platform on that branch. Obviously, I need to get up into the tree to do that. I'm pretty sure I could use conventional throw rope technique to get myself to just below the big branch, but I have no clue what I can do after that to get myself securely standing on top of that branch to survey things from there. I suspect that the next higher anchor point for a rope is well beyond throwing distance from there. Is there a separate category of equipment and techniques just to deal with trunks of this size? Or might I be better off just dragging a 40' extension ladder up there (it's quite a ways up a steep slope, but I guess it could be accomplished, with some difficulty?)

Maybe using a pole mounted sling shot will allow you to set your rope high in the canopy of the tree. There are also air powered cannons available that will shoot a throwbag/throwball well over 150' high.

Maybe you can use some kind of foothold to get to the upper side of the branch. If there is no foothold on the tree, try a sling, wrapped around the branch as a kind of stirrup and go on top like you would on a saddle of a horse.

Climbing trees with no branches can be difficult, but as long as you do it safely, it can also be really fun! There are a couple of approaches you can take -- the front-foot technique and the frog technique. The front-foot technique is best for skinny trees, like coconut trees. The frog technique can be used for trees that are a little wider. Use caution, since you can get hurt climbing any tree, branches, or not.

So many good advices here, thank you for sharing. I always wanted to climb a huge tree not far from my parent's holiday house in Portugal https://tranio.com/portugal/detached/ and been training and learning techniques for the past year. Hope I will be able to do it safely soon.

If the Big Shot won't work, it's crossbow time!