Value:  66¢ 1-ounce First-class rate (Forever)

Issue Date:  October 12, 2021

First Day City:  Otter, MT

Printed by:  Banknote Corporation of America

Printing Method:  Offset

Format:  Double-sided Booklet of 20

Sea otters (Enhydra lutris) are marine mammals found in the northern and eastern regions of the North Pacific Ocean.  They are the heaviest members of the weasel family and have the densest fur of any animal in the world.  While they can occasionally be found on land, the majority of their lives are spent in the ocean.

Male sea otters are larger than females and weigh between 49 and 99 pounds.  Females typically weigh 30 to 70 pounds.  Sea otters are unlike other marine mammals in that they don’t have blubber (fat) to keep them warm.  Instead, they depend on their thick, waterproof fur to do the job.  Because of this, sea otters spend much of their time fluffing and grooming their fur to ensure its oils are evenly distributed.  They also do this to keep an adequate amount of air trapped in their fur, which helps keep out water and aids in buoyancy.  Sea otter fur includes up to one million strands of hair per square inch, making it the densest of any animal.

Sea otters are well adapted to the cold and the largest population is currently found off the coast of Alaska.  Sadly, sea otter numbers dramatically declined due to the fur trade of the 18th and 19th centuries, and they continue to face threats today.  However, with serious conservation efforts, this endangered species can still be saved from extinction.