I would build a very small tripod type stand or get a tripod stand and cut the legs. I would then add some larger branches into the Russian Olive tree. This would get you off the ground just a couple feet into the branches to help break things up. Play the wind right and keep the wind in mind when picking your tree. If you can find a tree that meets both wind, shot oppertunity and has some sort of a back drop your in shape.
For example... that tree pictured has horable back drop although pretty, but if you were to build a tripod type stand that could sadle the trunk, put yourself just infront of that larger trunk that goes off to the left, just above where the smaller branch angles towards the camera; you could get away with much more than if you were on the ground. dang... that was a long sentence/thought
another thing that I would sugest that might go against the grain of normal thinking is keep the deer off of you. Take a couple stakes and run some rope from the tree to the stakes about 7-10 yards out. You dont want them to be right on top of you while your waiting for the right deer or the right shot. It doesnt have to be like a fence, just something about 2 feet up to discourge most deer from cutting right next to you. Of course, if the cattle are allowed to be in this overgrown spot, that might not go over very well. In that case make sure what ever your build is wisper quiet.
Good luck.
Dave