(CNN) -- A rider in the budget bill to keep the federal government in operation has triggered fury among some wildlife groups because it would remove certain wolves from the endangered species list.
The attachment affects gray wolf populations in Montana and Idaho.
"Right now, Montana's wolf population is out of balance and this provision will get us back on the responsible path with state management," Sen. Jon Tester, a Montana Democrat, said in a written statement. He said he wrote the language together with Republican Rep. Mike Simpson of Idaho.
"Wolves have recovered in the Northern Rockies," Tester added. "By untying the hands of the Montana biologists who know how to keep the proper balance, we will restore healthy wildlife populations and we will protect livestock."
Among those assailing the decision is the group Defenders of Wildlife, which operates the Campaign to Save America's Wolves. "Not only do these provisions substitute politics for science in the protection of endangered species, but they have nothing to do with the federal budget," the group says on a section of its website asking people to contact their lawmakers and urge that the provision be removed.
The rider goes beyond just removing these wolves from the endangered species list. It also establishes that the court system cannot overturn the decision, saying it "shall not be subject to judicial review."
The attachment restores a 2009 rule by the U.S. Fish and Wildlife Service that delisted the Northern Rocky Mountains gray wolf as a "distinct population segment" encompassing parts of Washington, Oregon and Utah, and all of Montana and Idaho. All of Wyoming is included in the "distinct population segment," but the delisting did not apply to Wyoming, the Fish and Wildlife Service rule said.
"The states of Montana and Idaho have adopted state laws, management plans, and regulations that meet the requirements of the (Endangered Species) Act and will conserve a recovered wolf population into the foreseeable future," the 2009 decision said. But Wyoming had not established "adequate regulatory mechanisms" to preserve the population, the rule said.
Environmental groups challenged the ruling in court. In August 2010, a federal judge overturned the rule, Defenders of Wildlife said.
The judicial battle has continued, but the budget provision would effectively render it moot.
While the rider has touched off controversy for its content, some are using it as an example of what they believe is a problem with the legislative system in general -- that completely unrelated issues work their way into important bills.
Rep. Ron Paul, R-Texas, said the inclusion of such a rider "doesn't make any sense."
"And it really shows how out of touch so many people are here in Washington and how unlikely it is that we will get to the bottom of our problems," Paul said in an interview this week with CNN.
In its 2009 rule, the Fish and Wildlife Service estimated the gray wolf population -- using 2008 figures -- at 1,639 total in the Northern Rocky Mountains. That included 491 in Montana, 846 in Idaho, and 302 in Wyoming.