From Deb's website:
Guided horseback rides are offered 6 times daily (8:30, 10, 11:30 a.m., 1, 2:30 and 4 p.m.) at the Tri-Circle D Livery at Fort Wilderness. The rides, which cost $42 per person, last approximately 45 minutes. Riders must be at least 9 years old and 48 inches tall and can weigh no more than 250 pounds. The horses are tame and walk pretty much single file during the ride. If you're an experienced rider, this ride may be too dull for you. If you've not had an opportunity to ride a horse before or have done so rarely, this ride may be just what you're looking for. To make reservations, call (407) 824-2832 -- reservations can be made up to 30 days in advance. It is strongly suggested that you wear long pants and that you do not wear open-toed or heeled shoes. To get to the Tri-Circle D Livery, you can drive to and park in the Fort Wilderness Visitor parking lot and walk; board the bus at the TTC and take it to the Outpost Depot bus stop; take the Fort Wilderness boat from the marina at the Magic Kingdom to the Fort Wilderness marina and then walk to the Settlement Depot bus stop where you'd then board the bus to the Outpost Depot.
