Looking for a lakeside campground surrounded by mountains, no cell service, and in eastern Canada? Look into Lac Escalier within Parc National du Mont-Tremblant. 

From the main entrance of the park it is about a 15 mile drive in on a winding road through the forest, half on pavement, and half on dirt. The campground itself offers 75 spots, a spigot for fresh water, and a center with clean bathrooms and two sinks for cleaning off your dishes. The campsites right by the water are of course the most desirable so book early (I suggest site #3). Book Here! 

Being on this lake (or Lac) is incredible. In the mornings there is fog rising off the lake due to the temperature differences. Brew a cup of coffee, grab a chair and hangout on one of the sand beaches while the sun burns off the fog. There are some great little sand beaches away from the "main" beach area if you are looking to be alone in the early morning. During the day you can rent kayaks, canoes, or paddleboards right from the campground and explore the lake/small rivers shooting off the lake. I highly suggest getting on the water and exploring. The surrounding forests you paddle through are fantastic. At night, head back to the beaches after cooking up dinner to enjoy the stars and the milky way.