To build a cattle head gate, place two 8-by-8-inch treated posts about 22 inches apart where the gate is to stand. Use post hole augers and a tamping rod to place 8-foot posts 3 inches deep, anchoring the cattle head gate. Secure 4-by-4-inch boards to the gate at ground level, 23 inches above that and at the top of the post. Fit the ground level board between the posts, but secure the others to the front side of the gate.
Attach all the boards together by drilling holes through them and screwing in 1/2-by-14-inch bolts. Secure a 4-by-4 inch board from the top of the right post to 10 inches above the 4-by-4 board at the bottom to use as the fixed side of the gate. Secure a 9-foot 4-by-4 board onto the ground level cross piece, leaving 10 inches of separation from the left post. This acts as the mobile side of the gate.
At the top of the right hand post, secure a 4-by-4 inch board using an 8-inch metal hinge. Leave at least 2.5 feet of the board above the post free to use as a handle. Use a 2-foot, 7-inch piece of 2-inch strap iron on each side of the boards to connect the mobile side of the gate to the handle. Secure the strap iron using a drill and 1/2-inch bolts.