Isn't that 3 miles based on a 6' tall person looking at another 6' tall person?
The fact that you are already well over 1000 feet and that cell towers are 500+ feet, I could see the farthest one being well over 40 miles away.
At the escarpment in Lewiston (only 400ish feet), depending on the refraction of the light on the lake, you can easily see Toronto (about 35 miles).
Go find out. It'll be fun. What else you got to do?