This is a sheet of 50 blue green 3 cent stamps from the United States. The stamp sheet features Grand Coulee Dam in a topic related to conservation. The stamps are ungraded and mint never hinged (MNH) with a face value of $1.50. The sheet is a great addition to any stamp collection and a valuable item for stamp collectors. 27mm separation of perforations between top 3rd and 4th stamps.