(MONEY Magazine) – Those growls echoing from Yellowstone, Glacier and other national parks this summer are not from disgruntled grizzlies but from indignant tourists socked with unexpected entrance fees. Visitors to a third of the nation's 337 parks are facing new or higher admission charges this summer, ranging up to $5 a vehicle and $2 a pedestrian per week. Last fall, Congress approved a temporary Park Service plan to double or triple fees at 62 of the most popular preserves and to begin charging admission at another 72. The Senate is now mulling a bill that would not only make the fees permanent but also increase them to $10 at such prime attractions as Grand Canyon and Grand Teton national parks as well as to override a 58-year-old ban against admission charges at Mount Rushmore. The fees have met with a glacial reaction. ''Why should people have to pay to look at their own land?'' wonders Tim Mahoney, wilderness expert of the Sierra Club. Senator Bill Bradley of New Jersey was so incensed by the proposed $1 tab to visit the Statute of Liberty, he introduced exempting legislation. Bristled Bradley: ''Lady Liberty says, 'Give me your tired, your poor.' She doesn't ask for a dollar.'' The bill passed and was signed by President Reagan in June. Nature lovers can take comfort in the fact that Congress also mandated that the increased revenues -- which doubled to an estimated $40 million this year -- can be spent only to enhance the parks and improve visitor services.