So I just looked it up, close to 900 miles. I think one day when I finally take a whole week off of work for a bike trip, I will do a Mon-Fri trip to Niagara Falls....also saw where they have a casino there, Seneca Niagara Casino....and I like to gamble....would be a great place to get a room for a night. What an awesome idea for a trip! If next summer is less busy than this one is, I may take off and go! I have plenty vacation time at work, so that isn't an issue.
Absolutely no weapons. Guns, mace, large knives. Big trouble if you have one. I hear even some Bear Sprays are not approved for Canada and can be confiscated. I crossed with camping gear, pocket knife and a hatchet without issues.
I have heard that if you are carrying extra fuel, it has to be in an approved container that has clear labeling that it contains gasoline.
Close to the border crossing, some stores may accept US currency but not all. Away from the border you must have a credit card or Canadian currency. I recommend having a card with the chip and a PIN number.
When I crossed with a friend on motorcycles, coming back into the US they asked my friend to pull forward and they questioned us separately to make sure our stories matched.
Also, call your insurance agent and ask for a proof of insurance for Canada. Makes things much easier if you get pulled over or have an accident.
Also, do you have to cross into Canada to visit Niagara Falls? Looking on Google Maps, it looks like most is all on the US side. Or is the best spots/views on the Canadian side?
Toronto is a very nice city, and is a reasonable distance from the falls. It's worth a detour
"Roads are just a suggestion, like pants."
The US dollar trades at a premium so you are better off using debit, credit or a currency exchange. You get about 1.30 in $CAD Any smart retailer would accept dollars at par or trade at a reduced exchange rate.