BILLINGS, Mont. — Aggressive gray wolf hunting took a toll in much of the Northern Rockies last year as the predator’s population saw its most significant decline since being reintroduced in the region.

Numbers released by state wildlife agencies show Wyoming’s wolf population down 16 percent from 2011, Montana’s down 4 percent and Idaho’s down 8 percent.

That was partially offset by population gains in eastern portions of Washington and Oregon, where wolf numbers have been climbing rapidly over the last few years but still remain low compared to other parts of the region.

The government’s original recovery goal, set in the 1990s, was at least 300 wolves in the region. Despite last year’s decline, the latest figures show the population remains at more than five times that level.

Overall, biologists tallied a minimum of 1,674 wolves across the five states at the end of 2012, a 6 percent decline.

Parts of Northern Utah also fall within the Northern Rockies wolf-recovery area, but the state has no wolves.

In Wyoming, wildlife officials this week said the state will halve its quota for the fall hunting season, to 26 animals.

The proposal will be up for public review this spring. It applies only to the state’s trophy game areas for wolves in the northwest corner of the state around Yellowstone and Grand Teton National Parks. Elsewhere in the state wolves are designated as predatory animals that can be shot on sight.

By contrast, in Montana and Idaho, wildlife officials have pledged to continue driving down wolf numbers to reduce attacks on livestock and big game herds.