AndyEck84: "Are there enough options to explore without going into Canada? "
I'm not exactly sure what you're implying with this statement, but crossing the border without proper paperwork, etc. and properly reporting back into the US upon your return is highly frowned upon by the Customs and Border Patrol of both countries. You could find yourself in a situation where fines are imposed or worse.
Virtually the entire trip on the Granite River will have you paddling border waters where you'll see international markers. Paddling the border waters is legal. Stepping onto Canadian soil is a not allowed.
If you don't have the proper paperwork, it's best to look for "options to explore" on the American side.