Diamond Peak Wilderness

Diamond Peak, at 8744 ft, crowns the western half of the Diamond Peak Wilderness in the Willamette and Deschutes National Forests in central Oregon (1). The wilderness was created in 1964 (from the smaller Diamond Peak Wild Area established 13 years earlier) and contains over 52,000 acres (2,3).

Diamond Peak from Oregon state highway 58.

Rhododendron bud.

This year’s precipitation and snowpack in Oregon currently is generally below median conditions (4). So, despite being early in the season I was able to hike with the family for a ways into the eastern side of the wilderness at about 5000 ft elevation without too much concern about losing the trail due to heavy snow cover. The forest consisted of a mix of pines (at least two species were present), firs, Douglas firs and hemlocks. Manzanita were common and there were also a few patches of rhododendron.

Interestingly, in this part of the wilderness both Oregon species of hemlock co-occurred, sometimes growing adjacent to each other. Mountain hemlock (Tsuga mertensiana) tends to be a higher elevation species, while western hemlock (T. heterophylla) tends to occur in the wetter climates of western Oregon, and at lower elevations (5). The two species can be distinguished both by their cones (longer in T. mertensiana) and by the color and organization of the needles on branches. Western hemlock needles tend to be an evergreen color arranged somewhat in a plane on the branches, while mountain hemlock needles are more bluish-grey and protrude radially from the
branches.

Foliage of both hemlock species can be seen (western hemlock in left and center, mountain hemlock at lower right). 

Distribution of western and mountain hemlock in the western US and SW Canada. Both species extend
north along the British Columbia coast to SE Alaska. Maps by USGS based on data from Little (1971).

With a mix of vegetation typically occurring in drier (pines and manzanitas) and more moist (Douglas firs, western hemlock, and rhododendron) environments, the wilderness appears to encompass a transitional area floristically. Snow prevented us from making it to any of the small lakes in the wilderness, but I am interested in exploring the western and central areas to find some mountain lakes. If they resemble the lakes I have seen in the Three Sisters Wilderness to the north and the Sky Lakes Wilderness to the south, they should be beautiful!


References:
(1) USGS topographic map, Diamond Peak, OR 1:24000 quadrangle.
(2) http://www.wilderness.net/NWPS/wildView?wid=157
(3) http://en.wikipedia.org/wiki/Diamond_Peak_Wilderness
(4) USDA, NRCS, SNOTEL data at http://www.wcc.nrcs.usda.gov
(5) Jensen EC & Ross CR. 2005. Trees to Know in Oregon. Oregon State University Extension Service.

Manzanita in bloom.