For example, the glacially carved Sawatch Range is known for its gentle slopes and great elevations, greeting hikers like a kindly old grandfather. Crumbling marine shale gives mountains in the Maroon Bells–Snowmass Wilderness the essence of a great manor house in disrepair; it’s a place where seemingly solid rocks embedded in the earth can pop out like rotten teeth. Pods of pristine peaks can be found in the sporadic outcrops and dramatic profiles of the Sangre De Cristo Range. Incredible sculptures of imposing granite define the remote Grenadier Range, daring you to enter their impressive kingdom.
There are many more subranges in Colorado, not to mention sub-subranges, such as the Spanish Peaks in the Sangre De Cristo Range of the Rocky Mountains. Geology is the primary factor in defining ranges, though categorization can be influenced by other whims. One example is the group of high Sawatch Mountains known as the Collegiate Peaks. These well-known mountains bear the names of prestigious eastern US universities, a far cry from the mellifluous names that had been bestowed upon them by native people. They differ little from surrounding Sawatch mountains, though it is interesting to note that they were initially grouped (before being named) according to mining boundaries.
However they are grouped on the map, as you spend more time in the mountains, you will begin to unveil the “personalities” of individual peaks. Until one actually sets foot on the slopes, the objective data and raw facts serve merely to foster our curiosity. Experiencing the mountain with your own senses reveals the spirit of the peak. Each journey to the high country transforms that two-dimensional mark on the map into a vivid memory. And whether the mention of a mountain brings to mind warm memories or recollections of chilling close calls, every step of the way will have been an adventure. Such are the adventures hikers yearn to live.
Geology and Biology: A Very Brief History
The definitive characteristic of the Rocky Mountains can be found right under your boots. Eons of change have put the “rock” into the Rocky Mountains. How these mountains were built is an intriguing tale. Fossils abound in compressed chronicles of stone, each representative of a past ecosystem. Dynamic transformations over the years have yielded a wealth of information and, conversely, have contributed to new scientific mysteries.
To summarize all the geological mayhem, Colorado’s rock has been shaped by three primary forces: plate tectonics, volcanic eruptions, and glacial polishing. Starting at the bottom of the pile are the Precambrian foundations of igneous and metamorphic rock, formed some 600 million years ago when most of planet Earth was a volatile, volcanic work in progress. Very little is known about this period. To put it in perspective, scientists believe the most advanced form of life at the time was a multicelled piece of slimy bacteria. (Similar life-forms can be found today in the back of my refrigerator.)
Then, 300 million years ago, the land began to rise up as continental plates collided. This created enormous sand dunes and other soft formations that served as a holding place for the mountains to come. Much of the trademark flagstone adorning the buildings at the University of Colorado in Boulder was formed in this era. Around 250 million years ago, the gnawing power of erosion had whittled down this sandstone, making space for great lakes of silty water and nearly uninhabitable swamps. Rising temperatures made life demanding for primitive creatures. If that wasn’t bad enough, an event known as the Great Extermination, in which life was eradicated on a global scale, made survival for our prehistoric friends an incredible act of endurance. This period of unexplained catastrophe ushered out the old, slimy age and introduced a new explosion of diverse life across the globe.
Between 250 and 100 million years ago, Colorado’s climate transformed flat, muddy swamps into great tropical forests. Incredibly dense and lush, these forests were ideal homesteads for a variety of dinosaurs. The really big boys called Colorado home, including the biologically enigmatic sauropods such as diplodocus and brontosaurus. These huge creatures had shockingly tiny brains, an anomaly that was offset by the fact that all they had to do was eat and grow bigger. Giant ferns grew in the verdant swamps, unchecked by dry weather or pollution. It was a great time for all. But, like all good things, it had to end.
Persistent erosion and changing temperatures began to have a profound effect on the landscape between 100 and 65 million years ago. Swampy basins lost their thickets of vegetation, resulting in marshy lakes that continued to expand onto flat tracts of land. All the hard work that plate tectonics had done to build up the land was nearly for naught. By the end of this era, most of Colorado was hundreds of feet underwater. This inland salty sea was host to incredible creatures, from gargantuan sea life to enormous flying reptiles. Seashells of ammonites and other critters from this period can be found today in several regions, notably the Elk and Gore Ranges.
From about 60 to 38 million years ago, the mountains began to rebound. An uplift of plates elevated mountains to modest heights: 3,000–4,000 feet higher than the seas below. Water rose with the land, pooling in isolated lakes or disappearing completely. Fearsome predators such as the jaw-some Tyrannosaurus rex roamed the land. As a whole, the animals and plants of this era show a gradual downsizing trend. The great giants found food sources vanishing or became snacks for smaller, more aggressive species. The times, they were a-changin’, setting the stage for the huge alterations in the land. Scientists speculate that the famous “doom asteroid” struck Earth in this time period. (The asteroid theory is based on high levels of iridium found in rock/plant samples, suspected to be a direct result of a huge meteor slamming into Earth in the Yucatan Peninsula near the modern-day city of Cancun in Mexico.) This collision affected life-forms of all sizes and triggered volcanic flows throughout the region. The impact was felt on a global level, yet it was only the first act in a show that would take place over the next few million years. The greatest changes were just around the corner… .
Colorado’s defining era was about to begin. Roughly 37 million years ago, massive continental plates were thrust into motion. This movement slid the North American Plate westward over the steadfast Pacific Plate, unleashing torrents of volcanic lava and ash. Incredible pressure pushed the land higher and higher, transforming those unassuming 3,000-foot hills into crowns atop enormous peaks. For millions of years, the land was altered as heavy rains washed away volcanic ash. Geologists are a bit puzzled that the mountains formed in the region that is present-day Colorado. Normally, tectonic-based ranges rise a mere 20–600 miles from the oceanic coast. These mountains rose up thousands of miles inland, possibly indicating a distinctive geologic event, which has never been repeated.
Dinosaurs too big (or perhaps too dull in the skull) for the new land to support disappeared. Smaller, smarter, and faster was the order of the day. The last titans gave way to more adaptable creatures. Mammoths, camels, bison, lions, and other warm-blooded creatures flourished, replacing the reptiles who had ruled this domain for millions of years. This golden era introduced the reign of the giant mammals, a tenure that was to be very short lived. Of all the creatures in this ancient mammalian menagerie, only a select few would survive into the modern day.
About 1 million years ago, things began to calm down, and the Colorado we know today began to take shape. Rock that had lain for millions of years under seas was now sky high. The Colorado Plateau rose up from huge faults and rifts. Plate motions made mountains out of molehills; the Sangre De Cristo and Wet Mountains ranges in the east are direct results of this powerful subduction. Volcanic eruptions added to the artistry. One example: The striking, crumbling precipice of Lizard Head Peak just outside of Telluride is the durable throat of a long extinct volcano.
Talus flows like liquid down to Lake Agnes at the foot of Mount Richthofen.
A mere 16,000 years ago, an ice age passed over the land. This was the last hurrah for the monster mammals, including the tusky mammoth. Only the hearty bison survived the advancing and receding glaciers, just