Politics stalked the national park system throughout 2007. From snowmobiles in Yellowstone to off-road vehicles in Big Cypress, it seemed natural resources and careful stewardship were trumped too often.

We heard both National Park Service Director Mary Bomar and Interior Secretary Dirk Kempthorne promise that science and careful stewardship would rule the national parks, and yet it seemed those promises fell short.

Not all the news surrounding the parks was negative, though. Congress approved President Bush's hefty funding increase for the parks, the National Park Foundation held a summit to explore partnership and philanthropy in the parks, and the Centennial Challenge was launched.

That said, here's a look at some of the top stories that rippled across the national park system in 2007:

• Yellowstone snowmobiles. Despite scientific reports that detailed how snow coaches were the best alternative for Yellowstone's environment, wildlife, employees and visitors, park Superintendent Suzanne Lewis approved a plan to allow as many as 540 snowmobiles per day into Yellowstone. That decision, which conservation groups have promised to test in court, could have consequences far beyond Yellowstone and Grand Teton national parks as I noted back in November.

  Rick Smith, of the Coalition of National Park Service Retirees, speaks of decision (1:00)
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• Fran Mainella points finger at Interior Department. A year after leaving her job as director of the National Park Service, Fran Mainella told the Traveler that Interior Department officials, not her office, called the shots on allowing snowmobiles in Yellowstone National Park.

  Fran Mainella talks to the 'Traveler' (4:34)
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• Jet skis. Conservation groups asked the Park Service to reinstate bans against personal watercraft in Gulf Islands and Cape Lookout national seashores as well as Pictured Rocks National Lakeshore. If the agency balks, the groups say they'll take it to court over the matter.

• ORVs in Big Cypress National Preserve. A decision by Big Cypress Superintendent Karen Gustin to reopen 20 miles of off-road vehicle routes was greeted by a lawsuit just before Christmas when a coalition of groups filed a lawsuit to overturn that decision.

• Katmai Bear Hunt. A groundswell of public outrage greeted the annual hunt of brown bears in Katmai National Preserve. Though hunting technically is allowed in the preserve, the seeming habituation of bears to humans created the impression that the bear hunt was akin to "shooting fish in a barrel" and prompted calls for the Park Service to end the hunt. Watch Video

• Park Service budget. President Bush proposed, and Congress approved, a hefty funding increase for the National Park Service. True, the $2.39 billion FY08 budget cannibalizes some sections of the agency's budget so its base operations funding will rise $153.4 million. But an increase is an increase.

• Centennial Challenge. In his fiscal 2008 budget request, President Bush proposed a Centennial Challenge with visions of infusing $3 billion, in a mix of public and private funding, into the park system as the National Park Service moves towards its centennial in 2016. Though controversial on several fronts, and falling short of his 2000 campaign promise to spend $5 billion to wipe out the Park Service's maintenance backlog, the initiative gained congressional approval, though not exactly as the president requested it.

  Kempthorne Announces Centennial Projects; Podcast (10:50)
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• National Park Foundation Leadership Summit on Partnership and Philanthropy. Private philanthropy long has played a crucial role in the construction and health of the national park system. To explore how philanthropy and partnerships can bolster the parks as they head to the National Park Service's centennial in 2016, the National Park Foundation in October convened a summit in Austin, Texas, to examine the possibilities.

  NPS Director Mary Bomar addresses Leadership Summit (1:45)
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• The Demise of the National Parks Pass. This much-loved $50 pass, which got its holder into as many parks as they wanted for a year, died on January 1 when the $80 America the Beautiful Pass came to be. However, congressional efforts towards the end of 2007 could spur the return of the National Parks Pass.

• Climate Change. In a telling report, the Government Accountability Office said the Interior Department has failed to provide the National Park Service with the tools it needs to cope with climate change and its impacts on the national park system.