Guard duties included standing as sentinels. Sentinels were posted at various locations throughout the fort: the powder magazine, post headquarters and around the perimeter of the fort. They were also responsible for guarding prisoners who were performing work details, such as working in the gardens or hauling firewood.
Anyone approaching sentinels were asked to halt and give a password or countersign. As a person approached, the conversation would generally go as follows:
Guard: Halt, who comes there?
Person: Friend, with the countersign.
Guard: Advance, friend, and give the countersign.
The person then advances and gives the countersign or password. The countersign would often be the name of a battle that the soldiers had participated in. If the person does not have the countersign, the guard will call for the sergeant of the guard.
Other duties of the sentinel included watching for prairie fires and keeping an eye out for soldiers misbehaving. In the event of misbehavior, the sentinel would report to his sergeant. In the event of a prairie fire, the sentinel would summon the other guards not on sentinel duty to come and fight the fire. The guards would form a bucket brigade, using water in leather buckets to fight the fire. Leather buckets do not need to be kept wet to hold water the way wooden buckets do.
Sentinels were generally relieved after two hours, and could then rest for four hours, before their next tour of duty. This rotation continued throughout the 24 hours of guard duty.