WYOMING — On Wednesday, July 2, the University of Wyoming’s deer migration initiative shared up-to-date migration data revealing that Mule Deer 665 arrived on her Teton Pass summer range after migrating 173 miles this spring.
According to the Wyoming Migration Initiative (WMI), Deer 665’s journey began on her winter grounds in the Red Desert, culminating near Teton Pass. Deer 665, who recently turned four years old, migrated for 35 days with 18 days of travel and 17 days in stopover sites. WMI tracking data on June 14 and 15 suggested that 665 gave birth to twin fawns, but visual sightings could not be confirmed, per WMI.
“This last leg of migration from June 4 through 8 really shows Deer 665’s determination to get back to her chosen summer range,” WMI wrote on Facebook. “Instead of staying in the remote Hoback Basin area where she was born in June of 2021 — and where thousands of other deer spend the summer — she followed her usual pattern and pressed on to Jackson Hole.”
WMI reported that on June 4, 665 left Little Granite Creek in the Gros Ventre Mountains, and by June 5, she had “hoofed it nine miles to upper Game Creek.” Later that evening, she descended a ridge south of Leeks Canyon and crossed the US 26/191 highway.
“This five-lane highway sees 10,000 vehicles a day, moving at 55 miles per hour, so she’s truly running a gauntlet,” WMI wrote. “It’s a reminder that every time we visit Jackson Hole or Grand Teton National Park, the animals we see along the highways may have migrated dozens or more than a hundred miles to reach that spot.”
GPS data indicates that Deer 665’s journey continued through hayfields and a golf course subdivision before she swam the Snake River near Wilson. By June 7, she was in the Bridger-Teton National Forest and climbing into the Teton Range above Mosquito Creek. Deer 665’s last day of migration was a four-mile jaunt over the Teton Range, taking her above 8,400 feet in elevation.
Finally on June 8, Deer 665 settled into her summer range on “a steep forested slope a few miles from the Wyoming/Idaho border.” Over the course of 10 days, she stayed close to the highway, ranging between 400 feet and 1,400 feet from the road, according to GPS tracking.
“Despite the car traffic and noise, Deer 665 knows that this summer range works for her, because she’s returned here for part or all of each summer since 2022,” WMI wrote. “We can’t be certain why Deer 665 traveled so far through other suitable habitats only to spend the summer next to the Teton Pass highway. It likely has to do with the availability of food, which is driven by precipitation. As long as there’s great food to eat, she doesn’t mind the traffic.”
WMI surmised that Deer 665 will work to put on body fat this summer while nursing her fawns. WMI will resume 655’s migration tracking map updates when she starts migrating again this fall.
