Two Mile Camp was a Wylie Camp that was located approximately two miles into Yellowstone National Park (geolocation)
1912 Topo Map shows the location of this Wylie Camp.
More information on the Riverside Wylie Camp can be found at Geyser Bob's.
A pullout and parking area still exist, but the camp was obliterated sometime after November 1934.
The location is labeled as "Madison River Overlook" on naturalatlas.com.
Labeled "Madison River Overlook" on naturalatlas.com