Video of wolverine kits at den on William O Douglas Wilderness

Deep in the William O Douglas Wilderness, east of Mt Rainier National Park, our wolverine mama, Pepper is raising two young kits.


Wolverine kits documented in the South Cascades for the first time in many decades.

Deep in the William O Douglas Wilderness, east of Mt Rainier National Park, our wolverine mama, Pepper is raising two young kits. See Seattle Times article.
Pepper and her 2 kits outside the den

On May 16th, our field crew returned from a 3-day snow camping trip into this remote, mountainous habitat with exciting news. Scott, Kayla, and I retrieved photos and video of Pepper and her kits from the den. This is the first reproductive wolverine den documented in Washington’s southern Cascade Range (Cascades south of Interstate 90) and the 3rd den in the state in over 50 years. 

Pepper's mate, an unknown male, at the den entrance

One of Pepper's kits, likely 3 months old today

In North America, wolverine kits are typically born in mid to late February so these kits are likely 2.5 to 3 months old today. 

Pepper displaying her unique chest blaze at a monitoring station

An unknown male, likely Pepper's mate, displaying his unique chest blaze

Previously, Scott and Kayla, our determined field crew, had gone above and beyond the call of duty to set a wildlife monitoring station far out in the wilderness. The station is designed specifically to identify individual wolverines from photographs based on their unique chest blaze and determine the wolverine’s sex, and possibly, its reproductive status. Here, they detected both the female wolverine nicknamed Pepper and an unknown male, which we assume is her mate. 

Scott and Kayla arriving at the den to check the cameras

The crew first discovered the den after wolverine experts examined photographs from the monitoring station, and determined that Pepper was lactating and thus raising young nearby. They followed wolverine tracks to the den after extensive searching. 

Scott looking for prey remains at a melted out snow cache - a "wolverine refrigerator"

They also followed tracks to several snow holes, where the wolverines had cached prey items deep in tree wells that act like refrigerators. These snow holes, where wolverines can keep food from rotting, are thought to be one of the reasons why wolverines rely upon snow for their survival.

Fresh wolverine track at our camp

During the last night of the trip - the 4th visit for Scott and Kayla - we were woken to a sniffing sound close to our tents. The next morning, we discovered fresh wolverine tracks in the snow under my socks that I had hung to dry on a branch, 4-ft from my tent. 

Wildy, the first wolverine documented south of I-90 in modern times

Our goal is to document the natural recolonization of wolverines into southern Washington and improve our understanding of how climate change threatens this rare and elusive carnivore.


First wolverine mama in southern Washington in many decades.

Pepper's unique chest blaze. 

In collaboration with the United States Forest Service (Naches Ranger District), we have documented a reproductive female wolverine, south of Interstate Highway 90 (I-90) in Washington's Cascade Range for the first time in a long time. We nicknamed her Pepper and she is also the first female wolverine documented south of I-90 in many decades. We first detected Pepper in 2016 at 2 wildlife monitoring stations on the Naches Ranger District. We collected hair samples from her in 2017  at another station as part of the Western Wolverine Conservation Project. Her DNA was genotyped to give her a unique ID, F37. This April, she was photographed at one of our runpole monitoring stations. From photographs, we confirmed with wolverine experts that she is lactating and therefore has kits (as long as they remain alive).

Pepper’s belly showing enlarged teats, evidence of lactation.

Our field crew followed Pepper's snow tracks along with a larger set of tracks, presumably of a male, and we detected a male wolverine at the same station as Pepper was detected as well as at a second station in the vicinity. 

Unknown male at another wildlife monitoring station.

Wolverines are slowly gaining ground in Washington after having been extirpated from the state in the 1950s due to excessive human-caused mortalities associated with predator control programs; however, their distribution had been largely confined to the North Cascades Ecosystem (NCE), north of I-90. As some of you may remember, the Yakama Nation made the first detection of a wolverine south of I-90, on the east slopes of Mt Adams in 2006. This was the impetus for founding the Cascades Carnivore Project. Now, this most recent evidence of a lactating female is the first indication that wolverines might be re-establishing themselves in the southern Washington Cascades. And while this is good news for wolverines and for wolverine conservation, there is evidence that their abundance throughout the contiguous United States is very low. In addition, they face new threats from by climate change and increased recreation.

Wolverines! Not only one individual in Washington's southern Cascades anymore.

It has been a busy winter. Scott and Kayla, our main field crew, have done an incredible job getting out to the remotest parts of our southern Washington study area (Mt Adams to Mt Rainier) into the heart of wolverine habitat.
We have begun using runpole stations as our newest survey tool. These are wildlife monitoring stations designed specifically to photographically identify individual wolverines based on their unique chest blaze and determine their gender, and possibly reproductive status. They also collect hair samples for DNA analyses. They were designed by wolverine researcher, Dr. Audrey Magoun, who knows more about wolverines than almost anyone else and has creatively designed these stations. The stations are set 10+ feet up a tree so they stay above the snowpack as winter progresses. Additionally, we have added features to ensure the detect Cascade red foxes. They also work well for detecting other rare carnivores such as fishers and Pacific martens. These stations require a bit more up front effort, especially while we got the hang of things, but they have the potential to provide valuable information that would otherwise require live-trapping individuals. Our goal is to determine whether wolverines are reproducing south of Interstate Highway 90 (I90) in the Washington Cascade Range. 
 Scott setting up the hair snagging device on the runpole.

Wolverine country.

First wolverine detected at a runpole station by our study.