He's b-a-a-ck!

We are so proud of Mr. Spock, he stayed with the Airstream all winter, making sure that everything was safe and secure. Now it is time to experience interesting geologic formations with Spock as we continue to use Albert B. Dickas' book, "101 American Geo-Sites you've gotta see," as a guide to our travels.

One of three Colorado geo-sites is 25 miles from where we are staying, in Boulder, the Boulder Flatirons.  The five ramparts that make up the Flatirons identity the Front Range of the Rocky Mountains. Three thousand million years ago, photo-NorthAmerica slowly collided with photo-south America and Africa, resulting in a tectonic fender bender - the  uplifting of the ancestral Rockies. Rivers then transported floods of debris off the ancestral Rockies in five separate formations.

Then, during the Cretaceous period, waters of the Western Interior Seaway (our old favorite!) advanced and retreated, resulting in three more sequences of strata measuring 10,000 feet thick. 

Around 65 million years ago generous volumes of magma invaded and uplifted the Precambrian basement, along with the overlying, younger sedimentary rock, which was bent into complex folds that extended for hundreds of miles. The modern Rockies were born. 

After erosion over time, the 50-degree angle of the resulting five Flatirons is evidence of the prodigious power of continental-scale mountain building, considering that the deposits were made in horizontal layers.

Mr Dickas is so impressed with the Flatirons that he uses a picture of them on the front of his book. 

That's it, our travel guide, a little the worse for wear.

All week it has been dry and sunny - today the rains came.

When we arrived in Boulder, using the geo-coordinates from Dickas' book, the Flatirons were shourded in fog. We though Mr Spock would have to be satisfied with a partial view.

The geo-coordinates took us to the City of Boulder's Chautauqua Park. We visited the Ranger Station at the Park and met Stacey, who met Mr. Spock. She looked up the weather forecast and told us a thunder storm was due in a few minutes. The good news - it would drive off the fog; the not so good news - there would be thunder and lightening.

The Ranger Station had some great exhibits. Mr Spock was intrigued by this big cat - a bobcat.

We sat in the car and ate our lunch during the thunderstorm, including a period of hail. We were rewarded with a pause in the storm and a somewhat clear view of the Flatirons.

On the drive back to Wheat Ridge, we had some wonderful views of the foothills,...

including this view back toward the Flatirons.