Millions of people visit Yosemite National Park every year to see the tall waterfalls and mountains. These mountains are a splendid sight when viewed from the valley floor. Lots of stores, hotels, and restaurants are needed to handle the crowds. Also, water, roads, and other service systems are part of the infrastructure( )that must be maintained. Unfortunately, these systems are starting to break down. It is not just in Yosemite but in national parks around the nation. Yosemite is thirty years old according to Dennis Galvin, a National Park Service worker. The park is not only old but worn out. Two or three times as many visitors come every year. That is too many visitors for the park to deal with. Four years ago a storm washed out a water pipeline in the Grand Canyon. The National Park Service had to send water trucks to provide water for the visitors. Last month pipe almost broke again and roads had to be closed for a while. Why hasn't the National Park Service kept up the park repairs? There is lack of money. The United States has 378 mountains, parks, and wilderness areas. Between three and four billion dollars are needed for repairs. Yosemite is one national park that does have money fro repairs. It has two hundred million dollars but cannot spend it any way it chooses. When the park workers started widening the road, they were forced to stop by the Sierra Club. The club claimed that the road work was damaging the Merced River that runs through the park. A Sierra Club lawyer, Julia Olson, feels that the infrastructure needs to be moved out of Yosemite. That way less pressure will be put on the already crowed park. According to the text, the Sierra Club is most likely to be   _   .
an environmental group an information center a travel service a law firm