While most of Yellowstone’s wolf packs were denning and having pups this spring, an unprecedented drama was unfolding for the Slough Creek Pack, one of the park’s most observed and popular packs. According to Dan Stahler of the Yellowstone Wolf Project, the Slough Creek Pack denned in April at the same den site as the previous year with at least two pregnant wolves, the alpha female 380F, and the beta female 527F. Within a few days of denning, an unknown pack of 12 wolves from outside the park’s boundaries came into the Slough Creek area and claimed residency outside the Slough Creek den site. Although the alpha male of this pack is collared, the collar is not emitting signals, and no one seems to know for certain from where this pack originated. The Unknown Pack repeatedly chased most of the Slough Creek wolves away from the den site, leaving the two Slough females trapped inside, probably with their new pups. Throughout the subsequent ordeal, both the second ranking (489M) and the third ranking (377M) males were killed by the Unknown wolves, delivering a serious blow to the organization and strength of the Slough Creek Pack. Eventually, the Unknown Pack succeeded in taking over the Slough Creek den: the two Slough females abandoned their den, their pups most likely died inside the den due to stress and lack of appropriate care, and the rest of the Slough Creek Pack broke into smaller groups and scattered throughout the northern range. The Slough wolves are still visible from time to time, and have recently begun to re-form as a pack in the upper Slough Creek drainage. The Unknown Pack had at least one pregnant female that denned, but she did not have a surviving litter. The Unknown wolves continue to occupy much of the Slough Creek Pack’s former territory; they are frequently spotted in the Jasper and Amethyst creek areas. The pack has recently scattered into smaller groups, which is not an uncommon pattern for summer wolf pack behavior.

In a painting commissioned by the Yellowstone Association, renowned Montana artist Monte Dolack brings two icons of Yellowstone together in one magical image—a grizzly bear witnessing Old Faithful Geyser erupting as the moon rises on a summer night. Bring this luminous scene into your home! A limited number of fine art posters signed by the artist (numbers 40-200 currently available) retail for $150.00, but are available to Yellowstone Association members for $127.50 plus shipping and handling.

Join this special group of Yellowstone Association members who provide help by making donations on a monthly basis. This reliable funding gives the Yellowstone Association the resources it needs to help ensure that Yellowstone will remain as it is today: a treasured refuge for our children, our grandchildren, and countless others who seek solace and renewal in its majestic wilderness. For as little as $10 a month—about the cost of a movie ticket—you can make a significant difference in the preservation of our world’s first national park. Look for sign-up opportunities in your next renewal mailing, or click the link below to sign up today! Be one of the first 150 people to join and receive a special gift—our way of saying thanks for your support! If you have any questions about our Yellowstone Guardians program, please call us at 307-344-2289.

There’s still plenty of availability in the Yellowstone Association Institute fall programs. Our Lodging & Learning packages combine in-field excursions with our naturalist guides, comfortable accommodations in park hotels operated by Xanterra, in-park transportation, some meals, and optional evening programs. You can still sign up for Autumn in Wonderland, Fall Wolf & Elk Discovery, Roosevelt Rendezvous, or Trails Through Yellowstone by calling 307-344-5566.