Colorado's rainforest - Clippings

American Forests, Autumn, 2002 by Charles Enloe

When most people think of Colorado, they think of a dry mountainscape covered by snow in the winter and heat in the summer. But two researchers have found that 64 million years ago, the area may have actually been a tropical rainforest.

In an article in the June 28th issue of Science, Kirk Johnson and Beth Ellis of the Denver Museum of Nature and Sciences reported finding fossilized evidence of a lush rainforest in Castle Rock, just 25 miles south of Denver. Ellis said the key to identifying the forest was the large size of the leaves and the presence of drip tips--rapidly tapering tips that are common in rainforests.

The findings were surprising because of the picture they paint about the recovery of life after a mass extinction that included the dinosaurs. Ellis said most researchers believed life would take 10 million years to reemerge strongly, but the rainforest was present just 1.4 million years after the dinosaur's demise.

It is not entirely clear how the rainforest developed, but Ellis said its growth may have been promoted by moist air coming off the much-larger Gulf of Mexico and the inland Cannonball Sea, which extended to the Dakotas.

Notably, the rainforest in Colorado contained incredible diversity. Ellis said that multitudes of plant species were found at every turn.

"You can get 30 to 50 different species in a given hole of 300 leaves," she said. "Then you'll find another 30 to 50 species in the next hole."