This issue was announced May 14th:

This booklet of 20 stamps features four scenes of the alert and playful North American river otter reveling in winter’s white landscape.

The original illustrations were rendered in pen and ink, with watercolor in shades of brown for the otters, using black for facial features and crosshatching. The wintry background is white, with blue water, light blue and violet shadows, and black crosshatching.

Art director Derry Noyes designed the stamps with artwork from illustrator John Burgoyne.

These stamps will be issued October 12th with a first-day city of Otter, Montana, but no “headquarters” first-day ceremony is planned.

Further updates on this issue will be posted below the large illustration, with the most recent at the top.

Updated December 6th:
The Scott catalogue numbers for this issue are:

• • 5648 Otter in Water
  • 5649 Otter, Tail at Right
  • 5650 Otter, Tail at Left
  • 5651 Otter in Snow
  • a. Block of 4, #5648-5651
  • b. Convertible booklet pane of 20, 5 each #5648-5651

Updated October 14th:
Here is the Digital Color Postmark first-day cancel for this issue:It measures 2.75″ x 1.05″. The standard 4-bar FIRST DAY OF ISSUE postmark is the B&W option.

Updated September 10th from the Postal Bulletin:
On October 12, 2021, in Otter, MT, the United States Postal Service® will issue the Otters in Snow stamps (Forever® priced at the First-Class Mail® rate) in four designs, in a pressure-sensitive adhesive (PSA) double-sided booklet of 20 stamps (Item 683500). These stamps will go on sale nationwide October 12, 2021, and must not be sold or canceled before the first-day-of-issue.

Otters in Snow, a new booklet of 20 stamps from the Postal Service™, features four different scenes of the alert and playful North American river otter reveling in winter‘s white landscape. The original illustrations were rendered in pen and ink with watercolor, in a color palette consisting of shades of brown for the otters, with black facial features and crosshatching. The wintry background is white, with blue water, light blue and violet shadows, and black crosshatching. Art director Derry Noyes designed the stamps with artwork from illustrator John Burgoyne.

No automatic distribution.

How to Order the First-Day-of-Issue Postmark:
Customers have 120 days to obtain the first-day-of-issue postmark by mail. They may purchase new stamps at their local Post Office™ or at The Postal Store® website at usps.com/shop. They must affix the stamps to envelopes of their choice, address the envelopes (to themselves or others), and place them in a larger envelope addressed to:

FDOI – Otters in Snow Stamps
USPS Stamp Fulfillment Services
8300 NE Underground Drive, Suite 300
Kansas City, MO 64144-9900

After applying the first-day-of-issue postmark, the Postal Service will return the envelopes through the mail. There is no charge for the postmark up to a quantity of 50. There is a 5-cent charge for each additional postmark over 50. All orders must be postmarked by February 12, 2022.

Technical Specifications:

Issue: Otters in Snow Stamps
Item Number: 683500
Denomination & Type of Issue: First-Class Mail Forever
Format: Double-sided Booklet of 20 (4 designs)
Series: N/A
Issue Date & City: October 12, 2021, Otter, MT 59062
Art Director: Derry Noyes, Washington, DC
Designer: Derry Noyes, Washington, DC
Illustrator: John Burgoyne, West Barnstable, MA
Modeler: Sandra Lane/Michelle Finn
Manufacturing Process: Offset
Printer: Banknote Corporation of America
Press Type: Alprinta 74
Stamps per Booklet: 20
Print Quantity: 300,000,000 stamps
Paper Type: Phosphor Tagged Paper, Block Tag
Adhesive Type: Pressure-sensitive
Stamp Orientation: Vertical
Image Area (w x h): 0.77 x 1.05 in./19.558 x 26.67 mm
Stamp Size (w x h): 0.91 x 1.19 in./23.114 x 30.226 mm
Full Booklet Size (w x h): 5.743 x 2.375 in./145.872 x 60.325 mm
Colors: Cyan, Magenta, Yellow, Black, Pantone 4261
Plate Size: 800 stamps per revolution
Plate Number: “B” followed by five (5) single digits
Marginal Markings: Header: OTTERS in SNOW • Twenty First-Class Forever Stamps • USPS logo • Barcode • Plate number in peel strip area • ©2021 USPS in peel strip area • Promotional text in peel strip area