BILLINGS, Mont. (AP) — A conservation group trying to create the largest nature reserve in the Lower 48 states said Tuesday it was scaling back its request to expand bison grazing in Montana, following strong opposition from ranchers and Republican lawmakers.

The group’s long-term goal remains unchanged: A 5,000-square-mile expanse of public and private lands with at least 10,000 bison in the north-central area of the state.

But that would happen more slowly than anticipated after the idea encountered resistance from surrounding landowners. They worry year-round grazing could destroy the range and that the reserve is displacing ranching families as it grows.

The American Prairie Reserve’s revised application to the U.S. Bureau of Land Management would allow bison to graze on about 94 square miles of public lands instead of the 450 square miles originally requested.

The Bozeman-based group does not want neighboring landowners to feel “bulldozed,” reserve vice president Pete Geddes told The Associated Press in advance of the public announcement.

Founded in 2001, the reserve is located on rolling grasslands along the Missouri River near the Charles M. Russell National Wildlife Refuge.

Massive herds of migrating bison once passed through the area before the animals were hunted to near-extinction in the late 19th century. Today the landscape is broken up by the fence lines of sprawling cattle ranches, many run by the same families for generations.

“We want our neighbors to feel very comfortable with our management,” Geddes said. “We have every intent as a conservation organization to make sure this range is in really good condition.”

In addition to paring back areas where bison grazing would be allowed, the revision would allow only seasonal grazing on most of the land instead of the year-round grazing originally requested. It reduces the amount of interior fencing removed — to allow bison and other wildlife to roam more freely — from 300 miles to 40 miles.

The changes would allow the reserve to increase its herd of about 850 bison by an additional 1,000 animals, said Betty Holder, the group’s land acquisition manager. The plan would remain in place for a decade before any more changes are sought, according to Geddes and Holder.

Opponents of the reserve were largely unmoved.

Deanna Robbins, whose family runs a ranch and hunter outfitting business near Roy, Montana, described the revisions as a “Trojan horse.”