Happy birthday to @greatsanddunesnps, which was established on this day 90 years ago! Located in south-central Colorado, this park is home of the tallest sand dunes in North America -- making them perfect for sandboarding and sandsledding. But if you visit in the summer be careful because the surface temp of the sand can reach up to 150°F! #greatsanddunes #greatsanddunesnationalpark #sanddunes #colorado #nps #nationalpark #nationalparks