So last year, a huge locust tree was among the trees that got cut down. As I was working through the wood, cutting it for firewood, I noticed the locust and cut it into 8 foot sections. Locust, specifically black locust, is the second best wood for posts around here. Bois d'arc, also known as Osage Orange, is the best, and red cedar is in third place.
I used the lowest trunk section as a post for a gate that I'm putting in to overwinter the hens in a sacrifice paddock. This post is an absolute beast, and Carla was able to help me lift it enough to get it into the back of truck. One of the reasons that locust works so well as a post is that not only is it rot resistant, but it's dense as all get out. This post is probably around 400 lbs. Down in the pasture, I was on my own, and used the truck to get the post dropped and set up right. Once the post was in the hole, I was just a matter of backing up VERY SLOWLY, using the tailgate as a lever. It worked.
A couple of 80lbs sacks of Quick-crete later, things were good to go. A heavy rain that night ensured that the concrete set up solidly.