first off Welcome to the forum. Secondly, I just went through this same situation with a hunting buddy of mine. He kept his in a dog pin for the first 2 1/2 months and two weeks ago we built a larger permanant pin. Heres what we did, the pin is 104' by 104' and on each corner there are burried telephone poles for strength. The fencing itself is 8 foot which we picked up from a local that was previously using it around his apple orchard. we then used pieces of strut (1 5/8 x 1 5/8" steel channel) every 8 foot in between the telephone posts. The hardest part is the gate, there we added an extra telephone pole and used a standard 4 foot high cattle gate. There are two issues here, one the gate has large areas that the deer can slip through and the other is that the gate is only 4 foot tall. what we did was attached 3 aluminum poles to the gate to extend up to 8 foot and then attached some orange fencing that you typically see surrounding jobsites to both the bottom and the top of the gate. This was the best we could come up with so if you think of anything better than that let me know. I can get you pictures if you would like just send me a pm and I will go out there and take some.