The National Parks Conservation Association report says pollution, tourism, mining, changes in the Colorado River and chronically under-funded budgets compromise efforts to protect resources and present a threat to the park, The Arizona Republic reported Tuesday.
"When you look at all of the challenges, you find out that the Grand Canyon is at risk, at grave risk," David Nimkin, the group's Southwest regional director, said.
"We made a deal when we created the national parks, that we would support them, and we need to do that."
The non-profit group, founded in 1919 by the first National Park Service director, aims to protect national parks by lobbying Congress and government agencies, often to stop policies and legislation that could harm resources, the Republic said.
To fix the issues raised would require significant amounts of money, changes in state and federal policies, and concessions by private businesses, but if left unchecked the very nature of the park could change forever, the association's report said.
Future visitors could find the most majestic views obscured, and habitats for native species could vanish, the group said.
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