Postcard US-8648356 raincrow U.S.A. 7 Aug, 2022 6 days 2,318 miles grayjay U.S.A. 13 Aug, 2022 Loading map... raincrow said: posted over 1 year ago Great Sand Dunes Naitional Park is in southern Colorado, USA. It has the largest sand dunes in North America. You need to sign in to leave a comment!