On the Canadian side, we stayed at Yogi Bear's Jellystone Park (800-558-2954). We liked the CG and would return. I can not help on the USA side.
Do not use your cell phone on the Canadian side. The costs are outrageous.
Lastly, consider using the "Find" feature (one of the tabs at the top of this thread). Search on Niagara Falls. Remove the check mark from "search only this forum". You should get at least a couple of dozen posts.
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
The Avatar Is Many Times Around The USA
Nobody Knows Your Coach Like Somebody Who Owns One Just Like Yours