You make roads and then tunnel off the roads. Pickup truck , tractor, skidder...horse...anything. Tie a rope around the oak and drag it out of the tangled mess.
That stuff makes me punchy. Tripping hazard, chainsaw gets caught on weed stems, you lose crap.
I can see how the forestry people come up with the idea of controlled burns. Or where the forest ecosystem benefits from fires.
Dont know about the little tree, honeylocusts have those weird dangly long seed pods. Don't know how long they stick around. Animals like them.
But they do have those thorns too.
The wood has a salmon color and coarse grain. Id have to go back and look at your first pics but I thought I remembered the wood looked very fine grained.
Cut it all up. I camp out in areas like that and clean the area up. I dont know about that underbrush, its tough to work in.
Maybe a burn barrel? Bonfire?
I make trails in my woodlot, the main network were here, some added. I used to drive horses cross country so they are horse carriage trails. Horse carriage, quad trails, snowmobile, cross country ski trails. Or just a walking path. The open path never goes to waste.
Have fun.
If you have money, rent a mini excavator with a thumb and landscape blade. It will be the most fun you will ever have with your pants on.