I spend much of my time flying in the North Maine Woods. Skis and floats are the best options for exploring this area as there are few landing strips. This area NW of Mt. Katahdin and over to Moosehead lake has a fair amount of float plane traffic in the summer. Some people monitor 122.85 and some never have turned a radio on.

However there are good grass strips to explore in Aroostook County. The strip at Fish River Falls (near Ft. Kent) is great and there are hiking trails to the water fall. Mars Hill also has a grass strip on the edge of town. This one is 1600' with a potato field on one end and tall pines on the other. Camping is allowed at both if you fly in. Here is a picture of my t-craft at the strip at Mars hill in 2011.

Patten Maine has a great grass strip. On this field there is a restaurant called "The Hanger", the food is hot and the prices are good.

Lincoln, Me also has a runway(paved) with a seaplane base and a campground on the river. This is my home airport. For a suggested donation of $10 you can stay at the camp ground have access to bath rooms/showers and I think there are kayaks to use.
Here is a picture of my current bird at the seaplane base.

Feel free to message me to find out more about these strips in Aroostook county, and I would recommend flying into Greenville for the seaplane fly-in. There are many wheel planes that attend and just as much happens at the airport as does at the waterfront.