This image shows the so-called Doubletop Mountain in the center background as viewed from the outlet of Grassy Pond, located in Baxter State Park in central Maine.
There is no description on the back of this card.
Grassy Pond is a name given to multiple locations in Maine. This one appears to be in Somerset County, near Holeb, Maine, and is quite small and shallow, less than 2 feet.
This image likely dates from the 1940s.