Federal biologists blame a variety of factors.
They say subsistence and sport hunting play a small role, but that the majority of wolves die of natural causes. Beyond that they can't pinpoint anything in particular.
"The last couple of years we've seen fairly pronounced declines. The prey populations, so far as we know, the moose, caribou and sheep populations are fairly stable. So we're not quite sure what's going on with the wolf numbers," said John Quinley with the National Park Service.
Biologists say the situation is more serious at the Yukon-Charley Rivers National Preserve.
The population there dropped 43 percent in one year.
Federal biologists believe sport hunting and subsistence hunting may play a larger role, along with the state's aerial predator control program.
In March, Alaska Fish and Game biologists shot and killed a pack of four wolves that frequented the preserve.
The government shut down sport hunting in the area to curtail the drop.
"There was the potential there to lose additional wolves that spend much of their time in the national preserve, so those factors caused us to institute a sport hunting closure," Quinley said.
Critics like Steiner say the drop is unacceptable.
"These numbers really, truly are shocking, and they should not have gotten this low. The Park Service should have acted years ago," he said.
"We're sort of at a yellow light, you know. We're going to keep monitoring the numbers and understand both the harvest and the natural mortality as best we can," Quinley said.
The National Park Service expects the population to be on the upswing by next year.
It conducts aerial wolf surveys twice a year in the spring and fall.
Contact Jackie Bartz at email@example.com