Rocky Mountain National Park in Colorado straddles the great continental divide. It’s home to the headwaters of the mighty Colorado River. This southern Rocky Mountain park is dominated by rugged peaks, evergreen forests and breathtaking alpine tundra.
Summers can be warm with lightning and thunderstorms and winters can be cold. This high elevation park sits between 7,800 and 11,800 feet above sea level.
As you enter the park heading west on U.S. Route 36, be sure to get out of the vehicle; stop, smell and listen. On a warm summer’s day the breezy air is filled with the butterscotch scent of ponderosa pine. These magnificent, three-needles-in-a-bundle, prickly, barreled-shaped cones and furrowed russet bark trees stand proud, guarding the gateway to the west. Listen to the wind and experience what John Muir, mountaineer and naturalist extraordinaire, wrote: “This species gives forth the finest music to the winds.”
Ponderosa pine is a very interesting tree that grows across the American West and up into southern British Columbia. It is fast growing in its youth yet very long lived, easily exceeding 600 years. That is a rare trait in the tree world. Moreover, these water specialists thrive in drier ecosystems, along with Rocky Mountain Douglas-firs and grasses.
Ponderosa pines and Rocky Mountain Douglas-firs evolved with frequent, low intensity surface fires. They do this by holding their branches at least 20 feet above the forest floor and 16-inch thick bark provides excellent insulation against the heat of the fast moving surface fires.
There are over half a million lightning strikes each summer in the southerly Rockies. Many of the ponderosa ecosystems on the east side of the park have been allowed to burn and so these forests resemble the grandeur of the ecosystem and the natural fire cycle.
Most ponderosa forests across the West, however, have been prevented from burning for the past 90 years or so. They are overcrowded, susceptible to disease and prone to insect attacks. When fire re-enters these forests, the seedlings and saplings growing underneath the mature ponderosa and Rocky Mountain Douglas-fir trees act as a ladder enabling fire to get into the treetops or crowns. Ponderosa pines and Rocky Mountain Douglas-firs have not evolved to contend with crown fires. The high intensity fires burning today across the west are killing mature ponderosa and Rocky Mountain Douglas-firs, removing seed sources and scorching forest floors.
As you travel along Route 36 it passes the edge of Beaver Meadow. In the autumn it is a renowned location to watch the 1,100-pound bull elk or “wapiti” — Shawnee for white deer — sparing for the rights to mate with a harem. The high-pitched bugle of rutting males sounds like the ancient forest primeval attracting thousands of visitors in October.
Rocky Mountain National Park has exquisite high elevation subalpine forests that are perfectly engineered for snow and cold weather. The pungent mountain air smells of subalpine fir and Engelmann spruce. These beauties with their tall spire-like crowns, evolved to shed snow and also hold it, dominate the high country.
Lodgepole pines, named because the Native Americans used the straight trunks to hold up their teepees, also live in these marvelous snow forests. Lodgepole pines are specially adapted to crown fires. Their cones open from the heat of fires providing viable seeds, which quickly germinate and re-colonize burnt-over lands.
The trees that live almost 2.2 miles above sea level at the top of the southerly Rockies are the venerable limber pines. They handle extreme cold, blasting winds filled with shards of ice particles and scalding summer sun. Admirable limber pines can live for well over 1,000 years.
These majestic subalpine forests of the southerly Rockies are crucial because they retain snow and release it very slowly in the spring and summer. This runoff feeds the headwaters of the Colorado River, which is arguably the most important river in the U.S. and certainly without a doubt the major freshwater river of the American West. The melt water from this river alone sustains tens of millions of people including the entire cities of Las Vegas, Phoenix, Tucson and San Diego.
Alarmingly, global warming has caused a steady decline, over the past 50 years, in the amount of snow received in the southern Rockies. Climate experts have predicted by 2035 that the Rocky Mountain snowpack could be further reduced by 60 percent, cutting summertime flow in half. Moreover, the harbingers of global warming — indigenous tree-killing bark beetles — have laced into the park and its plentiful food source, pine trees. Rising temperatures across the West have enabled adaptable mountain pine beetles an opportunity to speed up their breeding cycles; now two generations within one year.
Rocky Mountain National Park is about a 90-minute drive north of Denver. It’s a spectacular place to explore nature this summer with your family.
Dr Reese Halter is a distinguished conservation biologist and author of the award-winning “The Insatiable Bark Beetle,” Rocky Mountain Books.