This is a beautiful block of four stamps from the United States, issued in 1961-1970. The stamps are in the denomination of 6 cents and feature a range of natural history topics. The colorful design is sure to impress any stamp collector or nature enthusiast. The stamps are in great shape, with no hinges or creases, making them a perfect addition to any collection. They are uncertified but have been well-preserved for their age. This block is a great way to add some unique and historical stamps to your collection.