"National Parks, tiny cacti, fragile soils and a bunch of cows don't mix," he said. "Unfortunately, the service hasn't wanted to address this problem and has turned a blind eye to the trampling and degradation caused by cattle in Capitol Reef."
Capitol Reef officials were not immediately available for comment.
Grazing is allowed in Capitol Reef, which has two allotments for it, according to the lawsuit filed by Western Watershed Project in Hailey, Idaho, and the Cottonwood Environmental Law Center in Bozeman, Mont., against Secretary of the Interior Sally Jewel.
The Winkler's pincushion, listed as threatened under the Endangered Species Act, and the Wright fishhook cactus, listed as endangered, are both found within the grazing allotments in Capitol Reef National Park.
The lawsuit claims that a National Park Service email, dated Jan. 3, 2013 and obtained through the Freedom of Information Act, discussed the negative impacts grazing was having on the threatened species in the park.
"Field observations and discussion with the US Fish and Wildlife Service cause park staff to believe that present grazing and trailing patterns may jeopardize the continued existence," the lawsuit quotes the email. "Conservation actions required to protect the species would likely require significant changes in grazing and trailing."
John Meyer with the Cottonwood Environmental Law Center said this is a simple case.
"The park service has broken the law by failing to consider the impacts of cattle grazing on these rare plants," Meyer said in the statement. "Park service biologists have expressed concern that cattle are jeopardizing the continued existence of endangered cacti. Cows should never be allowed to drive endangered species into extinction, especially in a national park."
The National Park Service, the groups contend, is violating the National Environmental Policy Act and the Organic Act.
The groups are asking for the park service to "do the environmental analysis to determine whether or not there should be grazing," said Travis Bruner, executive director of the Western Watersheds Project. "But from our perspective it would be better if there was no grazing."