Montane, subalpine, alpine. Woodlands. Spring.
Trail along Bridal Veil Creek above Telluride, July 23, 2009; Madden Peak, June 23, 2004; Colorado Trail above Hillside Drive, August 12, 2020 and June 17, 2021.

Just above 11,500 feet ("tree-line" in the Four Corners area) trees are compressed and distorted by wind, the short growing season, intense sun, and snow pack.  These forces shape trees into krummholz (German for "crooked woods": the dwarfed, compact, crooked trees, some of which appear to be shrubs in the photos). 

Some slightly taller ten-to-fifteen foot krummholz are wind-blown into "banner trees", trees with no limbs on the wind side.

Krummholz may appear to be relatively young because it is so small, but, to quote the National Park Service, "Well-established krummholz trees may be several hundred to a thousand years old". 

Krummholz provides a haven for flora and fauna that cannot thrive in the nearby intensity. Krummholz is also a haven for humans wanting to picnic out of the wind.

Click to see Picea engelmannii in winter.