Michael Dax is the author of Grizzly West: A Failed Attempt to Reintroduce Grizzly Bears in the Mountain West (Nebraska, 2015). He lives and writes in Santa Fe, New Mexico.

Last summer, in its second attempt since 2010, the U.S. Fish and Wildlife Service deemed grizzly bears in the Yellowstone ecosystem recovered. When conservation efforts first began in the early 1980s, the bears’ population had dwindled below 150, but with roughly 700 grizzlies currently inhabiting the Greater Yellowstone Ecosystem, the Service removed federal protections and returned management to the states of Montana, Wyoming and Idaho.

But following a court decision last autumn regarding wolf populations in the Great Lake states that hinged on an obscure provision of the Endangered Species Act (ESA) related to geographically isolated species, the Service opened a comment period to accept public input on how treating Yellowstone grizzlies as a distinct population would affect other grizzly populations in northwest Montana and Idaho. This includes the Bitterroot Ecosystem, which I wrote about in my book, Grizzly West: A Failed Attempt to Reintroduce Grizzly Bears in the Mountain West, where there is still no resident grizzly bear population.

Recently, the Service decided to uphold its delisting rule, disappointing many activists but satisfying states like Wyoming that is planning to hunt as many as twenty-three grizzly bears this fall. Setting aside arguments that climate change poses significant stress to bears’ habitat and food sources, jeopardizing their long-term conservation, one of the biggest remaining threats to grizzly bears is the island nature of their current populations.

Although grizzly bears occupy at least four of the six recovery areas identified by the U.S. Fish and Wildlife Service, they have failed to migrate between those regions, raising questions about each population’s genetic diversity. Advocates have long argued that migration between these recovery areas will be key to long-term conservation efforts—a prospect made more difficult now that Yellowstone’s bears lack those key protections.

Grizzly bears were listed under the ESA in 1975, but genuine conservation efforts did not begin until the early 1980s with the release of the first Grizzly Bear Recovery Plan. In the plan, the Service identified the Greater Yellowstone, Northern Continental Divide, Cabinet-Yaak, and Selkirk Ecosystems as the main recovery areas. The Bitteroots and North Cascades in Washington state were added a few years later.

Although the Bitterroots once supported a robust grizzly bear population, by the mid-20^th century, overhunting had extirpated grizzlies from the region. Due in large part to a novel partnership between environmentalists and Idaho’s timber industry—the subject of my book—talks around reintroducing bears gained traction in the early 1990s, and many advocates’ appeals focused on the region’s proximity between grizzly’s two largest strongholds, the Yellowstone and Northern Continental Divide Ecosystems (NCDE). With a seed population back in the Bitterroots, proponents argued the region could serve as a stopover and genetic mixing pot for bears migrating between Yellowstone and the NCDE.

The plan slowly moved forward in fits and starts over the closing years of the twentieth century, and in November 2000, the Service announced it would begin reintroductions in the summer of 2002. But when the Bush Administration assumed power, it reversed course. The idea of returning grizzly bears to one of their historic homes proved to be too popular to abandon on its merits, but without funding, the program has sat on a shelf for the past seventeen years.

Of the six recovery areas grizzly bears currently occupy the Greater Yellowstone, Northern Continental Divide, Cabinet-Yaak, and Selkirk Ecosystems with estimates for the North Cascades ranging between zero and ten. (Earlier this year, Interior Secretary Ryan Zinke unexpectedly restarted planning for grizzly reintroduction in the North Cascades after he halted the program the previous year).

Each of these populations is doing better than it was in the 1990s with the Service planning to delist the NCDE population in the next few years. But still, grizzlies have failed to migrate between recovery areas and genetic stagnation remains as much of a concern as it was twenty years ago.

There have been some positive signs that with the proper protections in place, genetic exchanges between populations may not be far off. In 2007, a black bear hunter accidentally shot a grizzly bear in the northern Bitterroots. DNA testing indicated that the bear had traveled at least 140 miles from the Selkirk Mountains of Idaho’s Panhandle. More recently, two grizzlies were spotted in the Big Hole Valley, southeast of the Bitterroots in the summer of 2016. Scientists were not sure if these bears had traveled north from Yellowstone or south from the NCDE, but the fact they were spotted in areas long devoid of any grizzlies was heartening to many.

Sill, meaningful genetic migration has remained elusive, which brings us back to Yellowstone. The Endangered Species Act is designed not only to protect species, but the habitats upon which they depend. Without ESA protections, federal land managers no longer have to take into account how certain actions—like logging, grazing and mining—will affect bears, especially as they move out of the park and toward new areas like the Bitterroots.

By treating Yellowstone’s grizzlies as a distinct population and removing these consultation requirements, what had been an uphill battle, will likely become even more difficult.

While lawsuits challenging the delisting of Yellowstone’s bears are still pending, grizzlies will continue to expand their range, and it will be up to the states how those challenges are met. Of course, nearly two decades ago, we had the opportunity to restore grizzly bears to the Bitterroots, and if that project had proved successful, the nature of our conversations surrounding the future of grizzly bears could be much different today.