McKenzie Pass RNA

McKenzie Pass Research Natural Area (RNA) was established to represent lava flow with accompanying vegetation. The terrain varies from flat to rolling with a variety of small ridges and rock outcrops. The RNA is covered with small seasonal drainages that generally flow northwest. Depressions once carved out by glaciers contain several shallow ponds and meadows. Recent lava flows into the western, southern, and eastern portions of the RNA created a surface of sharp basaltic rock. Mountain hemlock (Tsuga mertensiana), subalpine fir (Abies lasiocarpa), Pacific silver fir (Abies amabilis) and lodgepole pine (Pinus contorta) dominate the RNA while occasional patches of Engelmann spruce (Picea engelmannii), western white pine (Pinus monticola), ponderosa pine (Pinus ponderosa), whitebark pine (Pinus albicaulis), Douglas-fir (Pseudotsuga menziesii), noble fir (Abies procera), and white fir (Abies grandis) are scattered throughout. The shrub layer is dominated by grouseberry (Vaccinium scoparium), thin-leaved blueberry (Vaccinium membranaceum), and dwarf bramble (Rubus lasiococcus). Herbs in the wetter meadows are dominated by water sedge (Carex aquatilis), beaked sedge (Carex rostrata), and Jeffrey's shooting star (Dodecatheon jeffreyi), while herbs in less common dry meadows are dominated by bluejoint reedgrass (Calamagrostis canadensis). There are also patches of Redwoods violet (Viola sempervirens), one-sided wintergreen (Orthilia secunda), beargrass (Xerophyllum tenax), and broadleaf lupine (Lupinus latifolius).