Transcript Title Slide (Project title)

The Dishman Hills: Or How We
Learned to Stop Worrying and Love the
Rocks
Taylor DeWitt
Ryan Pointer
Janae Kaschmitter
Kaelynne Byers
Introduction & Purpose
In this presentation we will discuss the rocks and
geological features of the Dishman-Mica
conservation area, as well as its history and
recreation activities available.
Our purpose was to research and identify the
geological makeup of the Dishman Hills.
Project Location
 Location: Spokane Valley along Appleway Blvd and Sargent
Rd.
 Directions: Take I90 E, take the Sprague exit (exit 285),
onto Appleway Blvd. Keep going east on Appleway until
Sargent Rd. Turn right on Sargent Rd. the Dishman Hills
parking lot is the first turn on your right.
Fig. 1 Map displaying route to Dishman Hills when going east in I-90. Satellite image courtesy of Google Maps.
General boundary
of the Dishman
Hills Natural Area.
Fig. 2 Google Map zoomout
showing size and scale of
Dishman Hills Natural Area
Site 3
Site 2
Fig. 3 Satellite zoom-in showing placement of site locations
Site 1
Parking
Spot
Site Geology
 Based on geological maps by R. E. Derkey et al.
 Area consists of pre-Tertiary quartz-feldspar-mica
orthogneiss (pTog).
 Intrusions of Tertiary-Cretaceous fine grained, biotitemuscovite granite (Tki).
 According to S. Babcock and B. Carson, the Dishman
Hills were formed when magma crept its way up to the
Belt-Purcell Supergroup and cooled into a granite.
 Granite was buried by Columbia River Basalts; and all
was eroded by the Missoula Floods.
Site Location: Spokane NE 7.5’ Quadrangle
R 44 E, T 25 N, S 19
Site 3
Site 2
Site 1
Parking
Spot
Fig. 4 Site locations on Spokane NE 7.5’ Quadrangle geological Map (Derkey, et al.,1999)
Site 1
At this site we found a subcrop of weakly metamorphosed felsic
orthogneiss. Veins of lighter colored quartz & feldspar are seen in the
rock averaging about half-inch to an inch in thickness with properties
consistent with pegmatite.
Fig.5 Pegmatite veins in subcrop embedded in
the ground. The lighter bands are majority
quartz & feldspar.
Site 2
This site also consists heavily of orthogneiss and
pegmatite. It has a well defined foliation as compared to
what was seen at site 1 (Fig. 6). The bands of quartzfeldspar-pegmatite are also thicker ranging 1-5 inches
thick (Fig. 7).
Fig. 6 Outcrop displaying the high grade foliation of
pegmatite and feldspar.
Fig. 7 Bands of quartz feldspar inside the pegmatite with
mechanical pencil for scale.
Site 3
This location of orthogneiss was cream colored due to sediment erosion from
the top of the outcrop (Fig. 8). Facing east from the outcrop, a subcrop of
orthogneiss and pegmatite can be seen where the pegmatite bands range
from several inches up to several feet wide (Fig. 9).
Fig. 8: Hillside of orthogneiss.
Fig. 9: Subcrop of pegmatite & orthogneiss (standard
notebook for scale).
Area History
 The Dishman Hills is a 530 acre area that was set aside
as a conservancy in 1966 due to the development around
the area. Residents wanted a place set aside that would
not be disrupted for the wildlife. It is protected by both
profit and non profit organizations.
 In July 2008, a wildfire broke out over the Dishman Hills
and destroyed 1200 acres of land and 13 homes. The
area has since recovered.
Recreation, Wildlife,
Plants, etc.
 The Dishman Hills boasts numerous trails for people to
wander and adventure along.
Fig. 10: Map of Dishman Hills Trails.
Recreation, Wildlife,
Plants, etc. (cont.)
 Dishman Hills has a wide variety of plant and animal
life
 Animal species include coyotes, weasels, squirrels,
chipmunks, marmots, porcupines, cottontail rabbits,
and white-tailed deer. Raptors, ruffed tailed grouse,
pheasants, and more than 50 species of butterflies
 Flora includes grass widows and arrowleaf balsamroot
serviceberry, wild rose, ocean spray, glacier lilies (Fig.
11) and bearded iris (Fig. 12).
Fig. 11: Field of Glacier Lilies
(Image Courtesy of Dishman Hills Conservancy)
Fig 12: A sample of Bearded Iris.
Conclusion
 In conclusion we learned that the Spokane area is
rich in geological history and natural beauty. And
fortunately for us, the Dishman Hills allows us to
explore that history and beauty without leaving the
city.
References
 Babcock, S., Carson, B. Hiking Washington’s Geology. Seattle: The
Mountaineers, 2000
 Derkey, R.E., Hamilton, M.M., and Stradling, D.F., 1999 Priliminary
Geologic Map of the Spokane NE 7.5-Minute Quadrangle, Spokane
County, Washington: Washington Division of Geology and Earth
Resources, Open File Report 1999-6
 Dishman Hills Conservancy. http://www.dishmanhills.org/
 Dishman Hills NRCA.
http://www.dnr.wa.gov/AboutDNR/ManagedLands/Pages/amp_na_dishm
an.aspx
 Dishman Hills Loop. Trails.com.
http://www.trails.com/tcatalog_trail.aspx?trailid=HGW036-019
 Google Maps
 Geranios, N. K. 2008 Wildfire Destroys 13 Homes in Spokane Area; 200
Evacuated. http://www.komonews.com/news/local/24385459.html