4-h trail changing the size of gate
The dimensions of our Trail class obstacles are described in the Pacific Northwest 4-H Horse Contest Guide. The gate latch must be 54-60" high and a minimum of 48" wide. The contest guide is vigorously researched and regularly updated by experts in horsemanship and youth development. In Oregon, proposed revisions first go to the State 4-H Horse Development Committee before being considered by the tri-state publication group.
If your county uses a gate that does not meet these requirements, you should bring it to the attention of your county extension agent.
For comparison, the United States Equestrian Federation, which oversees open competition and most breed shows, includes a section on Trail. They require that the gate and latch be approximately 60" high (page 15).
Given that 4-H includes more smaller horses and ponies that the average open show, our guidelines allow for a slightly shorter gate.
Trail obstacles are designed to mimic real life. The trail gate is sized similarly to what you would find in a pasture (60" is a common fence height for horses and cattle). We expect that a rider would need to bend down and lean to open a gate. That is what make this obstacle such a popular choice to demonstrate a rider's ability. I have seen riders and horses of all shapes and sizes navigate the gate successfully.
If trail is a very important class to a rider, they should consider that when selecting their horse. Each horse will excel at different events, and trail favors a mid-sized, agile, attentive, and patient horse. Matching the size of the horse to the size of the rider is also an important part of horse selection.
Good luck preparing for your county fair!