Always be prepared - the phrase is especially true when it comes to horses! Do you have a way to quickly and safely catch your horse in an emergency?
Keeping a halter wherever your horse spends a considerable amount of time - the stall, the pasture gate, etc, is a great way to be prepared for an emergency. If your horse gets loose, needs immediate medical attention, is in danger from bad weather or a fire, you will have a halter close by. This will save you from having to go run and find a halter when you need to immediately catch your horse.
Depending on your horse's living arrangements, that may mean you need more than one halter. One for stall, one for turnout. You can use an old halter that is still servicable as an emergency halter, or often times a rope halter or nylon halter can be found very inexpensively. Also these types of halters also won't rot or break easily if left outside, unlike leather.
Leave an emergency halter at the ready for your horse, and although hopefully you may never need it, if the situation arises, you and your horse will be ready!
The Info Pony