Hueco Tanks State Historic Site is a Texas historic site in the Hueco Tanks area, approximately northeast of downtown El Paso and just west of the Hueco Mountains. The park is popular for recreation such as birdwatching and bouldering, and is culturally and spiritually significant to many Native Americans. This significance is partially manifested in the pictographs (rock paintings) that can be found throughout the region, many of which are thousands of years old. Hueco Tanks is also widely regarded as one of the best areas in the world for bouldering (rock climbing, low enough to attempt without ropes for protection), unique for its rock type, the concentration and quality of the climbing, and after which the Hueco bouldering grades are named. In any given climbing season, which generally lasts from October through March, it is common for climbers from across Europe, Asia, and Australia to visit the park. Since implementation of the Public Use Plan, following a brief closure of the entire park due to the park service's inability to manage the growing crowds of international climbers, volunteer or commercial guides are required to access more than 2/3 of the park's area. Only North Mountain is accessible without guides, and then only for about 70 people at any given time. The park offers camping and showers for a small fee a day or, as is most popular for climbers, the nearby Hueco Rock Ranch offers camping where climbers can relax and socialize.