The northern terminus is at end of Summit County Road 1832 (some maps list as road as 1830) at GPS Coordinates: 39°50'13.5"N 106°22'08.4"W
The southern terminus is at the “Scenic Area" pull off on I-70, just past mile marker 196.5, right before Highway 91 exit at Copper Mountain.
Previous attempts have joined or left the Gore Range Trail at the Surprise Lake trail at the northern end, and have neither started nor finished at the parking area at the southern end. The signage for the trail at both locations is clear, as seen in attached images. These previous runs were ~45 miles, but deviated from at the the current Gore Range Trail at the northern end for a few miles, and cut off 3/4 mile at the southern end. It is not clear if this was the route of the trail at the time Bill Briggs ran it in 1990.
The mileage on the National Geographic #149, Eagles Nest and Holy Cross map adds up to 47.9 miles.
The attached GPX file shows 46.8, with 10,960’ of gain and 11,522 of descent.