When you think of the beach you certainly don't think Colorado, but maybe you should...
Travel + Leisure just named the top 25 best best beaches in America, and two are in landlocked states. The first is on Lake Tahoe is Nevada, and the other in Colorado.
The Colorado selection is Medano Creek, located in Great Sand Dunes National Park with the website saying in part, "visitors can enjoy wading in the water, tubing, skimboarding, and building sand castles. Because of the limited time-frame, it's best to plan your trip for weekdays in late May or early June."