Six more environmental groups have joined a lawsuit objecting to a U.S. Forest Service decision to allow the state to land helicopters in the Frank Church River of No Return Wilderness to dart and collar wolves.

In an amended complaint filed Tuesday, the Wilderness Society, Idaho Conservation League, Sierra Club and others joined a federal suit filed Dec. 31 by Western Watersheds Project and the Wolf Recovery Foundation. The groups’ main goal is to stop the landings, which they argue violate federal law, are unnecessary and were fast-tracked through the Forest Service without proper scrutiny.

“I think we’ve got a good shot to show that the Forest Service really should not have rushed this through,” Craig Gehrke, regional director for The Wilderness Society in Boise, said on Wednesday.

Federal regulations allow the state to fly over the wilderness area but prohibit helicopters and other vehicles from being on the ground. Fish and Game proposed to make fewer than 20 landings outside existing airstrips that will typically last less than 15 seconds, though longer landings are possible.

Regional Forester Harv Forsgren approved the limited number of landings by Idaho Department of Fish and Game employees on Dec. 22, writing that the state had already tried alternate methods and that the information would help both federal and state biologists. He also noted that similar landings have been done in recent years to capture bighorn sheep.

Wilderness advocates disagree, saying the landings set an unfortunate precedent. Gehrke also argued that the flight pattern and disturbance is different with the collaring work.

“Doing an aerial survey on a grid at a certain elevation is a lot different from suddenly breaking that formation, swooping down and chasing a wolf on a landscape,” he said.

Tuesday’s complaint asks U.S. District Judge B. Lynn Winmill to halt the planned landings and set aside Forsgren’s decision for being arbitrary and capricious. Western Watersheds and the Wolf Recovery Foundation also ask the judge to stop wolf killings in the Sawtooth National Recreation Area by the U.S. Department of Agriculture’s Wildlife Services and bar SNRA livestock grazing.

The filing states the flights are planned to start the week of Feb. 22; Fish and Game officials on Thursday said the date is not set yet but that they’re aiming for around that time of month. A hearing in front of Winmill is set for Feb. 18 in Boise.

As part of the suit, several members of the groups plan to be in the Frank Church around the time of the flights, including Veronica Egan, executive director of Colorado-based Great Old Broads for Wilderness. Egan said Wednesday she and two friends will fly into the wilderness from Ketchum and stay at the Middle Fork Lodge, where they’ll hike, snowshoe and gather wildlife data for later use.

“We feel that the landing of helicopters not only is illegal, but is way more firepower than is required for the job at hand,” she said.

The Forest Service and Fish and Game had no comment on the amended suit. But Fish and Game Deputy Director Jim Unsworth confirmed the state will go through with the flights.

“We’re planning on moving forward,” he said.