Great Sand Dunes National Park and Preserve has the tallest dunes in North America, formed by sand deposits of the Rio Grande. Many are over 750 feet tall! However, the park is not limited to sand dunes, there are also grasslands, shrublands and wetlands, alpine lakes, six 13,000-foot mountains, and ancient forests. Great Sand Dunes National Park and Preserve is open 24 hours a day, 7 days a week, year round, but Visitor Center hours can vary. See here for more info: https://www.nps.gov/grsa/planyourvisit/hours.htm Entrance Fees give you access to a 7-Day Pass Accessibility: The Interagency Access Pass for free or discounted admission for US Citizens or permanent residents with permanent disabilities is accepted here. The Visitor Center is mobility equipment and stroller accessible and has wheelchair-accessible bathrooms. There is an accessible mat that runs from the parking area to the edge of the sand and Medano Creek. Loaner balloon-tire wheelchairs that work when pushed through sand are available. Most Ranger-led programs are wheelchair-accessible. Please call 719-378-6395 in advance to make a reservation for equipment. The Dunes Picnic Area is wheelchair-accessible with packed, level paths and surfaces and accessible bathrooms. Service animals must be on-leash throughout the park. Additional accessible trails and facilities information can be found on the park website here: https://www.nps.gov/grsa/planyourvisit/accessibility.htm.