This might be a good warm up/practice for the GDMBR.
The Alberta Forestry Trunk Road. The road runs north-south, east of Banff & Jasper National Parks. It is shown on Alberta highway Maps.
You can get to/from the FTR on the south end from either Calgary or Banff, connect on the north end to Jasper, or connect to Saskatchewan Crossing on the Icefields Parkway in the middle.
The DIRT
Name: The Forestry Trunk Road
Distance: 1000 kilometers
Duration: 2 days (For folks on motorcycles)
Rating: class 2
Accomodations: Camping and lodges
Creator: Erik Schmidt
Location: Western Alberta
The FTR (Forestry Trunk Road) runs for 1000 kilometers along the foothills of the Rocky Mountains. 800 +- of the road is gravel surfaced with the remaining 200+- being paved.
For many the FTR is a destination onto itself, for many others it is used as warm up and a means to get to the northern roads like the Dempster. The scenery along the FTR is outstanding at times.
http://albertascampgrounds.com/camping-along-albertas-forestry-trunk-road/I hope this helps you plan your trip.
Wayne