There are four primary components to the Great Sand Dunes geological system: mountain watershed, dunefield, sand sheet, and sabkha. To read more about this, click here.

How many of you have hiked the dunes at Great Sand Dunes National Park and Preserve and noticed black patches or black ripples in the otherwise beige palette of the soft sand? What you are seeing are black magnetite grains in the sand. Magnetite is magnetic, and if you place a magnet on the sand, you'll pick up clumps of black magnetite grains. For real, and not an April Fool's joke! Cool, right?

On a clear, sunny day when 14,410-feet-tall Mount Rainier may be seen from miles away, the locals will tell you "The Mountain is out, today."

"Majestic figures of George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln, surrounded by the beauty of the Black Hills of South Dakota, tell the story of the birth, growth, development and preservation of this country. From the history of the first inhabitants to the diversity of America today, Mount Rushmore brings visitors face to face with the rich heritage we all share."

The 1,300-mile Mormon Pioneer National Historic Trail is not a single hiking trail but rather, a route traveled by Mormons who fled Nauvoo, Illinois, to the Great Salt Lake Valley in 1846-1847. Along this route you can see some amazing landscapes while learning about this route and the hardy people who traveled it.

"In the middle of a bustling urban setting, this 72 mile river park offers quiet stretches for fishing, boating and canoeing, birdwatching, bicycling, and hiking. And there are plenty of visitor centers and trails that highlight the fascinating human history of the Mississippi River."

"Kitchens were one of the busiest rooms in the home not just for cooking of meals, but also washing of laundry."

"The Mescal Historic Mining District was a small-scale producer of tungsten and tin in the Mojave Desert, and produced tin for domestic World War II stockpiles. Due to the temporary nature of mining activity on the site, some of the features have deteriorated, but the character and significance of the site remains strong."

Mug House, built around 1,100 - 1,200 AD, was so named from the discovery of three pottery mugs tied together with a rope and hanging in one of the rooms of this cliff dwelling in Mesa Verde National Park.

"Rolling hills, deep river valleys, and the world's longest known cave system. Mammoth Cave National Park is home to thousands of years of human history and a rich diversity of plant and animal life, earning it the title of UNESCO World Heritage Site and International Biosphere Reserve."

Cave tours are a unique and immersive way to understand and safely explore Mammoth Cave. You can go to the website to learn more about tours, tickets, and times.