I find the relief shading on most maps covering that large an area ends up understating the actual steepness of the terrain. Many people will rely on that one map for navigation b/c it encompasses such a huge playground of options regardless of their activity. This can lead unexperienced or unfamiliar users into trouble very easily. My preferences would include:
- aggressive, exaggerated relief shading.
- a physically large map with a high degree of detail. Possibly even a set of 4 maps sold as a package so that you don't have to keep opening one gigantic one.
- marking unhikeable terrain (the most serious stuff)
- a reflective strip to find the map in the dark if it gets lost on the trail.
- be very thoughtful of where the folds are and minimize key points happening along edges or corners.
- virtually every map I've ever seen of the area cuts off the backside of Cheakamus Lake. I've yet to get out too far that way but I've always been curious if it's doable to follow the Cheakamus Lake trail out and hike up around Singing Creek to Singing Pass. Doing a loop like that with an overnight at Russett Lake Hut would be pretty sweet.
- Bear, wildlife info
- Emergency numbers and service locations. Cells do work in a surprising number of spots thanks to the antenna locations.
- good eats (could sell advertising)
- good hitch-hiking spots
One other thought might be to have one map for each side of the valley, one on each side of the map. Most adventures will take place on one side of the highway or the other. You could draw each map something like this with the highway being a natural (to-the-eye) divider:
You could play with the map-to-info balance and likely would end up with more space to fit a better map image and/or include more area.
Looking forward to seeing it someday. Good luck.