Rocky Mountain National Park, Colorado

From Boulder, we headed up to Estes Park and then across into Rocky Mountain National Park. Unfortunately, the combination of deep snow above 12,000 feet and constant thunderstorms, forced us to make this mostly a drive through experience.

One of the most interesting aspects of the park is the treeline ecology. At about 12,000 feet in elevation, the trees suddenly stop. Unlike the Pacific Northwest, where treeline is controlled by the depth of the snowpack, the Rocky Mountain treeline is formed where temperatures drop below -40F in the winter. At that critical temperature, the sap in the phloem freezes, expanding and tearing the vessels open and making it impossible for those trees to survive. That seems to be one of the key ecological features of treelines in many mountains on Earth and at the Arctic Circle.

In addition, you will notice that the valley bottoms are also devoid of trees. That occurs where cold air sinks down from the mountains in winter and settled into the valley bottom. These freezing temperatures also kill the trees down there. But, the middle elevations between 9,000 and 12,000 feet stay just warm enough to continue to support an Engelmann Spruce/Subalpine fir forest. In addition, herbivores like Rocky Mountain Elk also trim back seedlings, keeping the meadows open for grazing.

The Rockies are somewhat frustrating in summer, with the constant daily thunderstorms preventing us from hiking at the higher elevations. Here you can see them rolling in even before noon.

All our grand plans of hiking a 14'er or so were being crushed day after day by these storms. We were basically being forced to stay below 10,000 feet.

Here you can see a creek meandering through the meadow-covered valleys

Given the weather, we simply did a short hike up the headwaters of the Colorado River toward its source, in and amongst aspens, cottonwoods, and firs.  It did begin to rain on us after about an hour, so eventually we turned back. He headed out the west entrance and then off to Steamboat Springs, where we stayed overnight. We ate dinner that night at an excellent Italian restaurant.