The tower is a sacred site for many Plains Indians (Plains Indian) as well as a popular site for rock climbing. The month of June is a particularly important time in the Plains religious calendar, when many individuals visit sacred sites to conduct religious services. June is also one of the more popular climbing months. This has created conflict in the past, as some American Indians feel that climbing should be prohibited at the site either permanently or during that month, while some climbers feel this would unfairly restrict their use of public lands. The National Park Service began a voluntary climbing hiatus program at Devils Tower in 1995. Although some individuals continue to climb during June, many have chosen to avoid doing so out of respect for others' religious traditions.