Conservation groups reacted swiftly Wednesday to a bill introduced by Republican Sens. John McCain and Orrin Hatch, among others, that would block the U.S. Interior Department from implementing a 20-year moratorium on new uranium mining near Grand Canyon National Park.

The Northern Arizona Mining Continuity Act of 2011 (pdf) seeks to block the ban proposed by Interior Secretary Ken Salazar within a 1-million-acre buffer zone around the nation’s most iconic national park. Conservation groups say the move is needed to protect the Colorado River watershed and to prevent industrialization of an area heavily reliant on outdoor recreation and tourism.

“We are disappointed in this jobs-killing legislation,” said Roger Clark, air and energy program director at Grand Canyon Trust. “Uranium mining threatens thousands of tourism-related jobs in northern Arizona. Salazar has found the right balance between protecting Grand Canyon and the $700 million tourism industry while leaving promising mining areas further from the national park open to exploration and mining.”

McCain countered that Salazar’s move would be a job-killer.

“The Department’s proposed mining withdrawal would kill hundreds of potential jobs to ‘save’ the Grand Canyon from the same form of uranium mining that conservation groups once supported,” McCain said. “It also threatens to unravel the spirit of the Arizona Wilderness Act and will raise significant questions for future Wilderness bills if agreements to accommodate responsible land uses are neither genuine nor enduring.”

House sponsors of the bill include Arizona Republicans Jeff Flake and Trent Franks.

“It is unconscionable that Senator McCain and Representatives Flake and Franks are seeking to undermine protections for Grand Canyon and its watershed and showing so little regard for the people of Arizona, including all of those who expressed strong support for protecting these lands from uranium mining and the pollution it produces,” said Sandy Bahr, director of the Sierra Club’s Grand Canyon Chapter.

The Grand Canyon has been under growing pressure from surrounding mining and power-generating activities, including haze from coal-fired power plants.

Colorado is increasingly in the crosshairs of uranium mining and milling controversy, including a legacy of contamination from the state’s uranium heyday in the 1950s, 60s and 70s.