The Madison Plateau Trail was an old wagon road, turned hiking trail, turned cross-country ski trail, and now an abandoned nearly-impassible trail after the 1988 fires and subsequent treefall.
Location
The Western end of the trail began at the old Riverside Mail Station. The trail went up the Madison Plateau and ended at Marshall's Mail Station near the confluence of the Firehole and Nez Perce Creek.
Construction
The trail was initially intended as an easier route for mail between the two mail stations than the path through Madison Canyon.
It was constructed around 1885. An article in the Salt Lake Tribune, November 14, 1885 said, “The Government is making a direct road from upper Firehole Basin to the west boundary line of the Park at the foot of the mountain. This shortens the distance thirty miles and will give a much easier road in grades. [...] Most of the work has been done and the rest will be finished in the early spring."
This passage from npshistory.com provides great context.
Shortly after arriving in Yellowstone on July 2 [1880], [Norris] met O. J. Salisbury, a partner in Gilmer & Salisbury Company, who requested his assistance in selecting a new coach and mail route connecting the Utah Northern Railway with the headquarters at Mammoth Hot Springs. The existing route along the Madison River, which required much bridging, was impassable for parts of the year and was considered dangerous by many.
After two days of exploration, an acceptable route that cut south from the Madison River at Riverside, was found. [57] Salisbury left men to construct a mail station at the Riverside cutoff, while he proceeded East to secure his mail contract. Norris, who once considered the mountainous area south of the Madison River inaccessible, was surprised to find "a dry, undulating, but beautifully timbered plateau, allowing a judiciously located line of wagon road with nowhere an elevation much in excess of 1,500 feet above the Forks of the Fire Hole." [58] This route, some six miles shorter than the Madison Canyon route, would be cheaper to construct and maintain and also would open up new observation points for scenic and geologic interests. [59] Traveling through the beautiful pine forests on an August trip to the West Entrance via the new route, Norris commented that this dry route was preferable to the often snow-covered and flooded canyon route. He felt that this would be the preferred route. However the other, if necessary, could be used for part of the summer. [60]
Name of the Trail
The name of the trail changed over the years and was known at times as:
Madison Trail (Yellowstone National Park Trails - link)
Madison Plateau Trail (link)
Madison Plateau Road (P.W. Norris's Annual Report for 1880)
Norris Slide (Yellowstone Place Names: Mirrors of History)
To Beaver Cañon (US War Dept Report of the Cheif of Engineering 1900 - link)
Old Fountain Pack Trail (link)
Current Status
These folks hiked the whole trail in 2008. Great photos!
1958 USGS Topo