Instructions
Attach the snap end of the lead rope to the horse's halter and lead the horse to where you would like to tie it up. Choose a spot that is far enough away from other horses to prevent kicking or biting. The post that you tie the horse to needs to be solid and strong enough to hold if the horse decides to pull back.
Run the free end of the lead rope through the ring or around the post that you are planning to tie the horse to, going from either top to bottom or left to right. There should be 2 to 3 feet of rope length between the snap attached to the halter and where it loops through the ring or around the post. The first section of rope runs from the horse's halter to the ring, the second section runs from the ring to the ground.
Grasp the second section of rope. A few inches below the ring, make a fist-sized loop with the rope by twisting it in a circle. Hold of the loop with your right hand and pass it just underneath the first section so that half the loop is showing on either side.
Use your left hand to reach through the left half of the loop from the underside. Pass your left hand over the first section of rope and grasp the second section of rope, just below the loop. Pull it back through the loop, leaving it folded. Pull it just far enough to create a second loop that is running through the first. As you are pulling the second loop through, pull downward on the first loop to tighten the first loop around the second. There should be a few feet of lead rope hanging freely.
Undo the knot by yanking on the free end. This will pull the second loop back through the first loop. Some horses eventually figure out how to undo slip knots themselves. If you have a horse who likes to do this, run the free end of the rope back through the second loop once the knot has been tightened.
How to Tie a Slip Knot for Horses
Always use a slip knot when tying a horse. If the horse spooks and pulls back, the slip knot will allow the handler to quickly undo the knot and release the pressure that the horse is putting on itself, reducing the chance of injury or destruction of property. Slip knots are easy to learn and can be made with any type of lead rope. This type of knot is also commonly referred to as a quick-release knot. Some variations between the style of these knots exist but the basic structure of the knot is the same.