This is a Tree Fishing cache. You might be able to climb to it but it is a bit dodgy. Please do not retrive it if you can not replace it.
Some tree fishing caches have a high difficulty and a low terrian. I beleive it should be the other way around. The terrian rating is increased because you need a tool. This is the same as if you needed a boat to access a cache. These type of caches are often a 4 or 5.
There is a bit of GPS bounce . You are looking for tree that is of a different variety.