Here is the information I have about how to book the carriage rides:
Carriage Rides are now available at the Tri-Circle-D
Ranch at Fort Wilderness Resort and Campgrounds! The
30-minute rides are offered between 6 p.m. and 10 p.m.
nightly. Each ride costs $30 (per carriage, NOT per
person). Riders may be picked up at either
the Wilderness Lodge or near Crockett's Tavern at Fort
Wilderness. There are two carriages available; one
accommodates four adults and two children, the other
accommodates two adults and two children. Reservations
are suggested, but not required, and may be made by
calling 407-824-2832.