From the landing approach to the airport in Jackson Hole, WY with the dramatic Tetons exploding from the flat plains below, my first visit to the northern Rockies was both exhilarating and depressing.

I was in Wyoming to join journalists, academics, a Nobel Prize winner, and NRDC experts on a trip to explore the impacts climate change is already having on the wilderness around Yellowstone National Park. Coming from the flat urban canyons of Chicago, the towering rugged beauty of real mountains is always a rush but it was quickly tempered by the sobering view of vast red forests blanketing the panorama during most of the drive to Dubois 75 miles away.

We had come to see those red forests.

This is not the picturesque beauty of the northeast's fall foliage. In Wyoming and the rest of the Greater Yellowstone wilderness red trees are dead trees. One species in particular, the white bark pine, is dying at alarming rates and putting the entire ecosystem at risk---but especially the resident grizzly bears and neighboring human communities.

What is killing the trees?

Many scientists believe that drought and warmer temperatures caused by global warming are major contributors to the escalation of the die-off by opening the door to an array of new threats.

As the west heats up a fragile balance that has existed for millennia is quickly falling apart. Those changes are noticeable at higher elevations where small changes have huge impacts. And as a foundational species, Whitebark pine are likely heralds of problems we will see throughout the U.S. The trees are being assaulted by mountain pine beetles which are able to move into higher elevations and attack in greater numbers due to milder winters that no longer kill off their larvae. This threat is exacerbated by the increasing rate of infection by a non-native pathogen, white pine blister rust. Over 50% of the whitebark pine forests in the Northern Rockies have been lost in the last 40 years as a result of the new infection. The trees have no defense for the invaders and are now in danger of being functionally eliminated in the Greater Yellowstone Ecosystem in the next 10 years.

"So what," you might say. "There are plenty of other trees to take their place."

Actually, no. These are trees with a special knack for colonizing new spaces and making them available to other species. Without whitebarks, you won't see new trees in this ecosystem.

Besides, whitebark pines have a special relationship with one of the region's most iconic species. Yellowstone grizzly bears face an uncertain future without these trees. Females rely on caches of white bark pine cones and their high fat content when preparing to hibernate. And since the pines are an important food source; fewer whitebark pines probably translates into fewer grizzly bears.

For folks living in the region, there is a far-more compelling concern---the clear correlation between whitebark pine cone production with human-bear interactions. When there are a lot of cones, bears do not venture as far for food. Fewer cones means more bears out foraging and coming into contact with people. Those contacts are bad for both parties. Bear/human conflicts rarely end pretty...

And so, with that in mind, the words of Dr. Jesse Logan hung in the air very eerily for me and the rest of the folks on the tour. We were hiking high in the Wind River Mountains when we heard him state, "These trees are dead. They don't know it yet, though. I guess they are zombie trees..."

The image was apt.

Tree after tree we saw were pocked with hundreds or thousands of tiny holes bored by the mountain pine beetles. The trees looked healthy aside from the small mounds of red saw dust, or "frass," which you cannot spot until you are right up on the tree. Underneath, the beetles had carved galleries---little bark hallways where larvae had already hatched and would eventually emerge as adults ready to colonize another tree. The trees without red leaves would have them soon.

Red is dead.

But all is not lost. Dr. Logan and NRDC's own Louisa Willcox have put together a team that is monitoring the Yellowstone ecosystem, all 20 million acres of it eventually, to establish a data set of infection via bush plane over flights. The flyover data is augmented by a growing community of interested hikers, naturalists, and outdoorspeople who are also capturing information on the spread of the beetles and pine rust in the tree species. Hopefully, that information will help to get some stronger protections for the species in the future---and save the Greater Yellowstone Ecosystem.