Ecotourism activities include spelunking, rappelling and hiking. Extreme sports include mountain biking, rappelling, spelunking and more. Visiting or exploring caves for recreation may be called "caving", "potholing", or "spelunking". Mountain climbing and spelunking is permitted at the park. Tours include a daytime walking tour, spelunking tours, overnight tours, and educational field trips. Throughout the 1950s, "spelunking" was the general term used for exploring caves in US English. Abseiling and spelunking trips can be organised with some local adventure companies. It has scheduled openings for guided exploration arranged with Austin area spelunking organizations. It is open to the public for walking tours and spelunking. Many visitors have tried to find the silver through spelunking. Lee has compared his writing process to spelunking.