The U.S. National Park Service must find a balance in an inherently conflicting mandate that calls for preserving and protecting ecological systems while providing for the public's enjoyment of natural resources through recreation. This conflict is especially intense in the case of fisheries management. Although most of the waters in Yellowstone National Park are managed as catch-and-release fisheries, some individuals still hold that fishing (like hunting) in the park is in fundamental conflict with the goal of preservation. An important element in the National Park Service's balancing act is the economic value of recreation activities. This paper uses the results of a 1993 survey of anglers at five blue-ribbon fishing sites in and near Yellowstone National Park to estimate the economic value that anglers attach to their fishing experiences. We estimate that fishermen place a value of between US$172 and $977 on a day of fishing. For Yellowstone National Park, these estimates translate into a total value of between $67.5 and $385 million for angling within the park. These estimates can provide some guidance to managers in deciding between alternative uses of the Greater Yellowstone's freshwater resources.