Seeking Route Advice - OH -> SD -> MT -> BC

Hello All,

Long-time lurker is seeking routing advice for a trip from Ohio to
Montana this summer. Would like to structure the route so as to take
in Mt. Rushmore. I'll be flying a 180hp 172, and am planning for 3
hour legs VFR only. Destination is Cut Bank, Montana to cross the
border into Lethbridge, B.C., head over to CAQ4, and join up with a
caravan of folks from Flynorth.com to fly the Alaska Highway into
Alaska.

Getting from home base in Ohio (Weltzien Skypark, 15G) to Rapid City,
I can handle planning myself because that's mostly flatland flying,
which is what I'm used to. But, once I leave KRAP (a terrible
identifier, IMO), there aren't a lot of great direct routes to KCTB
jumping out at me that keep me somewhat close to an airport in the
event of an emergency. Likewise, an efficient "airport-hopping" route
that avoids overflying relatively mountainous terrain isn't readily
obvious to me.

The same holds true for the leg from CYQL to CAQ4, which calls for
crossing the Rocky Mountains.

Can anyone whose done this kind of thing before offer some routing
suggestions? They'd be much appreciated.

Darrell Clay
Cleveland, OH
N3978S