in case any others are thinking of this next yr , cycleworld mag ran an article on the Mex-Canada trial , I think someone is selling GPS waypoints on it. this is no small undertaking, be prepared.
under regional forums post your request, some ( me for north central wash state) are working on a trail BC-MX as close to the cascade Mt range as possible. lot of scouting to be done.
taking a route through eastern washington, eastern oregon, central nevada has plenty of dirt roads, very remote, easier then a trail ride. plan your gas, food, water well, some towns on the map are no more then a ghost town w/ no services. stunning scenery, desert from BC to mexico. this section of the latter 2 states is THE most remote part of the lower 48 US,
nice people too.