The Thorofare pack was one of the first packs that naturally formed in Yellowstone after reintroduction. Wolf 030F dispersed from the Nez Perce pack that was released in Yellowstone in April 1996. Wolf 035M dispersed from the Lone Star pack (also released in Yellowstone in April 1996) after his mate (036F) died. These two wolves formed the alpha pair of the new Thorofare pack and produced 6 pups in 1997. In January 1998, the alpha female (030F) died in an avalanche and the alpha male (035M) was killed by wolves from the Soda Butte pack. The 5 remaining pack members were all pups that remained together through the winter and into the spring of the next year. Later, they seemed to split up. One pup was seen near Heart Lake in June 1998 and another was seen with 2 other wolves in Grand Teton National Park. The last observed pup known to be born into the Thorofare pack was seen in October 1998.