Below is the link to the RCMP site regarding firearm possession in Canada.
Firearm Users Visiting Canada - Royal Canadian Mounted Police
We live not too far from the border and travel to Canada frequently through both Buffalo and Niagara Falls. It's just simpler to leave our firearms home. Not only is the wait on the bridge(s) long enough, but the added BS of bringing a firearm will add substantial time to your crossing. Plus, for us, our everyday concealed carry pistols do not meet Canadian requirements because the barrels are too short. Even a S&W 38 spl J-frame is too short. I guess you need a full sized cannon, because the Canadian thinking is that a short barrel is too easy to conceal. Duh!
Finally, are you from NY State with handgun permit? If not, I suggest you leave them home. Even though you may have them secured in compliance with FOPA, that doesn't mean that you won't run into trouble with Emperor Coumo's anti-gun gestapo. You can be in complete compliance with FOPA, but they will still detain you and it may still add plenty of grief and aggravation to your trip.
Enjoy your trip to NF. There's lots to see and do.... Maid of the Mist (by boat to the bottom of the falls), Whirlpool Jet Boat (jetboat ride through the huge rapids in the lower Niagara River) and prepare to get wet!, Niagara on the lake (quaint village at the mouth of the Niagara river at Lake Ontario) with lots of restaurants and shops, tunnels beneath/behind the Canadian horseshoe falls, Helicopter tours, etc, etc, etc. Make sure you leave plenty of time, as lines tend to be long, depending on the time of year.