Items you will need
Poles, logs or ground rails
Traffic cones or similar markers
Make sure each piece of equipment is safe for both horse and rider. Remove any nails that might be in your poles or ground rails. Familiarize yourself with horse trail course rules and regulations you will be abiding by in competition to make sure you include required elements and avoid prohibited obstacles. For example, sometimes dismounting is a required element, and sometimes dismounting is forbidden. These may differ by group or association and also may differ by state, so look into it ahead of time.
Make sure you space your ground rails according to whether the horse will be walking, trotting or cantering over them. Usually, walk-overs are spaced 15" to 24" apart, trot-overs are spaced 3' to 3 1/2' apart and canter-overs are spaced 6' to 7' feet apart. You may need to make minor adjustments to these based on your horse.
How to Build a Horse Trail Course. Whether you are looking to practice trail courses with your horse for recreation or in preparation for showing, building a trail course is useful for both you and your horse. Most obstacles are relatively easy to obtain and set up, and the course will offer you and your horse some challenging fun.
Preparing the Trail Course
Zone an area large enough to trot your horse 30 feet, lope your horse 50 feet and set up at least six different obstacles as suggested in the following steps. This may be in an arena or in the open as long as there is sufficient space.
Obtain eight to 10 logs, poles, ground rails or cavaletties. They may be of varying lengths and diameters, but make sure you are able to move them if you need to.
Buy traffic cones, training cones or similar markers. You will need at least three.
Get an old mailbox. For a permanent fixture, attach the mailbox to a post you can drive into the ground. For a temporary fixture, secure the mailbox to a barrel or other moveable stand.
Find a gate with which to practice. If you do not have access to an existing gate, you can usually buy freestanding gates specifically designed for horse trail courses, or you can build your own. Hinge gates and rope gates are popular options, but try to avoid wire gates.
Round up additional objects such as a rain slicker, fake flowers, barrels and if possible, a bridge. The bridge should be at least 36" wide and secure enough for a horse to walk over safely.
Setting Up the Trail Course
Place at least three ground rails that the horse will walk, trot or canter over and one that the horse will side-pass near or over. The poles may be raised and may be in a straight, zigzag or curved line.
Build an "L" or a "V" shape with four of the poles. It should be wide enough that the horse can pass forward and backward through it.
Place three ground markers spaced apart in a straight line for the horse to weave through, both forwards and backwards.
Set up the mailbox obstacle in such a way that you can open and close the mailbox while mounted.
Construct the gate in an area clear of the other obstacles or set up other obstacles near an existing gate.
Add optional obstacles to the required trail course obstacles. Set two barrels on opposite sides of the arena with an object on one barrel that you must pick up and carry over to the other barrel. Put the bridge among the other obstacles to practice riding both around and over it. Position fake flowers in the traffic cones, near the mailbox or on the bridge.