[header] How to build a horse fence gate [title] Purchase treated wood. [step] Choose a sturdy, weather-resistant wood. You'll need two gateposts, plus enough wood to build your gate. 
[substeps] For a typical horse, each post should be at least 8 feet (2.4 meters) long, so it stands about 5.3 ft (1.6 m) above the ground. For tall draft horses or jumpers, each post should be 12 ft (3.7 m) long, and stand about 8 ft (2.4 m) above the ground.