A wooden butt plug was made for the larger end where the powder was poured to fill the horn. Sometimes these larger plugs were permanent. It all depended on the equipment available to make a removable plug. Most of the powder horns made on the frontier had permanent plugs on the large end. The one in the picture is permanent. The smaller tip had a hole bored into it for a spout to pour the black powder into the gun. The plug was fitted to the hole.
Sometimes fancy brass fittings were used for the pouring spout and plug. Ridges were carved into the horn to attach a carrying strap. Some people decorated their powder horn with fancy carvings called scrimshaw. Others only put their name or initials to identify the owner. The initials in the bottom photo are that of Anson Perry Winsor, the first ranch manager here at Pipe Spring.
Who: Pioneers used the powder horns until guns which did not need the black powder were available. Indians who had some of these early black powder guns had powder horns, too.