[Illustration: {uncaptioned}]
The great mid-sections of our high mountains, lying between 8,000 and
10,000 feet in elevation, make up a life zone called Montane, also known
as Canadian. Since most of our Colorado mountains are granite, the
typical soils in this zone are granite gravel. Some mountains, however,
are faulted blocks of sedimentary rock which have weathered into clay
and sand soils. The annual rainfall in this zone is over double that of
our plains. This has resulted in forests of lodgepole pine, aspens, and
of several species of spruce, with stream banks lined with willows and
water birch.
This abundance of vegetation has produced enough humus to build rich
black soil in the bottoms of the narrow valleys. In this zone grow a
wealth of flowering plants. The principal adverse conditions against
which they struggle for existence are: a fairly short season from spring
melt to fall freeze; and more tree shade and more competition from tree
and shrub roots than they would choose. The steep hillsides in this zone
may be quite rock covered. Between the rocks small amounts of good soil
may form, and under loose rocks moisture stays for a long time. Trees
thrive on these hillsides, but in open spots and beside rocky outcrops
flowers get their chance. The columbine grows in perfection in this
zone, extending downward into the foothills and upward to timberline.
The building of highways in our mountain areas has introduced new
conditions of which some plants are quick to take advantage. The
stirred-up soil of new road fills and drainage channel construction will
be colorful with fireweed, purple fringe, brown-eyed-susans, with here
and there penstemons and asters by the second or third season of their
use. Local irrigation accomplished by highway drainage and the use of
snowplows, as well as distribution of seeds by animals and even by cars
that use the roads, all play their part in this quick restoration of
life in the soil that has been torn up.
The picture at the top of this page was taken near Mary’s Lake in Estes
Park. The mountain shown is Twin Sisters. Its slopes are a fine hunting
ground for flowers.