I read the other day that the last week of the year is the most profitable for charitable organizations. With that in mind, here are some national park-related organizations that can benefit from your charity as the 2009 tax year comes to a close. Not only will you get a tax benefit, but you'll be helping provide for the national parks.

* The National Park Foundation. Chartered by Congress, this organization exists to raise funds that can be invested into the National Park System. Projects this organization funds are many and diverse. To name just a few the foundation has helped underwrite programs to bring inner-city youth to national parks, contributed to efforts to combat invasive species, and invested in preserving park settings.

* The National Parks Conservation Association. This group does much of the heaving lifting when it comes to legally challenging activities that could be detrimental to national parks, such as off-road activities or mining or air-pollution sources. But the NPCA does more than that. It maintains a presence in Congress to lobby on behalf of the parks, works to educate policy-makers and decision-makers on topics such as climate change, and has an arm that studies ways to improve park management.

* Friends of Acadia. This organization is a prime benefactor of Acadia National Park, working to help the park obtain in-holdings of private land, maintain trails, and organize volunteers to befriend and help the National Park Service take the best care possible of Acadia.

* Friends of Apostle Islands National Lakeshore. This group helps tend to some of the minor details -- providing toilet paper for the lakeshore's restrooms is one example -- to maintaining historic structures, providing bear boxes, and even publishing the lakeshore's newspaper.

* The Blue Ridge Parkway Foundation. Like many units of the National Park System, the Blue Ridge Parkway doesn't always have all the money it needs to help properly manage the 469-mile-long parkway that stretches from Shenandoah National Park to Great Smoky Mountains National Park. That's where the foundation comes in, raising money through things such as license plate sales and outright donations, to perform such services as bringing the national parks into classrooms and working on maintenance projects along the parkway.

* Friends of Big Bend. Among the projects this friends group has targeted is a new video for Big Bend National Park's visitor center, night-sky-friendly lighting for the Chisos Basin, and a design charette for a future paleontological exhibit.

* Crater Lake Trust. The trust is working to underwrite the Science and Learning Center at Crater Lake National Park, develop distance-learning programs, and fund interpretive exhibits.

* Friends of Congaree Swamp. This advocacy group for Congaree National Park works to raise the park's profile, restore and maintain ecological systems, and enhance educational and interpretive programs.

* The Friends of the Smokies. Along with working to raise public awareness of Great Smoky Mountains National Park, this friends group raises money to invest into the park and organizes volunteers to work in the park.

* Friends of Hawaii Volancoes National Park. Field seminars, forest restoration work, and fund-raising to support programs at Hawaii Volcanoes National Park such as the Junior Rangers are among the efforts shouldered by Friends of Hawaii Volcanoes National Park.

* Friends of Sleeping Bear Dunes. This past year saw the friends group begin work on design for the Sleeping Bear Heritage Trail, collaborate with staff of Sleeping Bear Dunes National Lakeshore to develop inexpensive guidebooks, and continue restoration work on the Thoreson Farm House.

* Gettysburg Foundation. In supporting Gettysburg National Military Park, the foundation works to "enhance the preservation and understanding of the heritage and lasting significance of Gettysburg."

* The Glacier National Park Fund. Efforts by the fund to support Glacier National Park range from underwriting research in the park and preserving historic structures to helping keep the park's iconic Red Jammers on the Going-to-the-Sun Road.

* Golden Gate National Parks Conservancy. This non-profit partner to Golden Gate National Recreation Area works to support the diverse research, conservation, and interpretation programs for the NRA's many areas.

* Grand Canyon National Park Foundation. Wildlife research, trails work, educational programs, and historic preservation are among the areas the foundation works to support at Grand Canyon National Park.

* Grand Teton National Park Foundation. Bear boxes, wildlife research, and visitor center improvements are among the projects supported by this group in Grand Teton National Park.

* Great Basin Foundation. This group has been working on providing educational and interpretive materials for the visitor center at Great Basin National Park and maintaining trails in the park.

* Lassen Park Foundation. The foundation works to maintain hiking trails, provide funding for wildlife research, and develop youth programs in Lassen Volcanic Park,

* Friends of Mammoth Cave National Park. Education, enhancing international scientific cooperation, and improving the visitor experience are among the tasks tackled at Mammoth Cave National Park by this friends group.

* Mesa Verde Foundation. The big project on the foundation's plate is raising funds for the Mesa Verde Visitor and Research Center.

* National Parks of Lake Superior Foundation. This group operates under a large umbrella, looking after the needs of Apostle Islands National Lakeshore, Isle Royale National Park, Pictured Rocks National Lakeshore, Grand Portage National Monument, and Keweenaw National Historic Park. Projects include trails maintenance, stabilization and restoration of historic buildings, youth education, and teacher materials.

* The National Park Trust. The trust is "the nation’s only organization dedicated to the completion, and the full appreciation, of the American system of National and State Parks through the identification of key land acquisition needs and opportunities."

* Point Reyes National Seashore Association. Field programs, summer camp, and wetlands restoration are among the many projects this group supports at Point Reyes National Lakeshore.

* Rocky Mountain Nature Association. This is the friends group for Rocky Mountain National Park, where it invests quite heavily in education, interpretation, and resource-related projects. The association also underwrites fellowships for researchers and offers summer programs for youth.

* The Sandy Hook Foundation. "Established in 1989, the foundation's goal is to nurture and protect all of Sandy Hook including Fort Hancock, a National Historic Landmark site in Gateway National Recreation Area, by supporting programs and projects of environmental, historic, and cultural importance."

* Sequoia Parks Foundation. This group works on behalf of both Sequoia and Kings Canyon national parks. Projects range from rangers in classrooms to trail maintenance, "artists in the backcountry," and wildlife research and restoration.

* Statue of Liberty-Ellis Island Foundation. Restoration projects at the Statue of Liberty and Ellis Island are key among the work tackled by this foundation.

* Voyageurs National Park Association. Procuring funds to purchase in-holdings in Voyageurs National Park, supporting endeavors to clean the air that descends on the park, and working with the park's staff to meet unfunded needs top this group's to-do list.

* Washington's National Park Fund. The foundation raises funds that can be distributed for projects in Mount Rainier, Olympic, and North Cascades national parks. Projects funded in 2009 ranged from youth outreach in Mount Rainier and bird inventorying and monitoring in North Cascades to elk studies and fisher recovery in Olympic.

* The Yellowstone Fund. This foundation works in many areas of Yellowstone National Park, from campground restoration and wildlife research to providing support for the park's rangers through the restoration and outfitting of historic patrol cabins in the park's backcountry.

* The Yosemite Fund. This organization, which just merged with the Yosemite Association, raises dollars that can be put to work in Yosemite National Park restoring trails, improving habitat, and conducting scientific research.

Likely there are other park-related groups out there, so if you don't see your favorite park represented here, Google for it.