Field Trip #2: Columbia River Gorge to Historic
November 3, 2013
12:30 PM to 5:30 PM
Register by: 10/14/13
Description of Activities:
The trip will start by traveling upriver (east) on I-84 following
the Lewis and Clark trail along the Columbia River and into the
scenic Columbia River Gorge to historic Bonneville Dam. Beautiful
Multnomah Falls will be the first stop, where participants can stretch
their legs and purchase refreshments.
Falls is the tallest waterfall in the State of Oregon, with
a total height of 620 feet in two separate drops. Underground springs
Mountain are the year-round source of water for the waterfall,
augmented by spring runoff from the mountain's snowpack and rainwater
during the other seasons. A foot trail leads to Benson Footbridge,
a 45-foot (14 m)-long footbridge that allows visitors to cross 105
feet (32 m) above the lower cascade.
Bonneville Dam and Lock is a concrete, gravity dam consisting of
dam structures that together complete a span of the Columbia
River between Oregon and Washington states at River Mile 146.
The dam is located 40 miles (64 km) east of Portland, Oregon in
River Gorge. The primary functions of Bonneville Lock and Dam
are electrical power generation, fish passage and river navigation.
The dam was built and is managed by the U.S. Army Corps of Engineers.
Electrical power generated at Bonneville is distributed by the Bonneville
Power Administration. Bonneville Lock and Dam is named for Army
Bonneville, an early explorer credited with charting much of
the Oregon Trail.
A Public Works Administration project of President Franklin D.
Roosevelt's New Deal, portions of Bonneville Dam were designated
a National Historic Landmark District in 1987. The project's first
powerhouse, spillway and original navigation lock were completed
in 1938 at a cost of $88 million to improve navigation on the Columbia
River and provide hydropower to the Pacific Northwest. A second
powerhouse was completed in 1981 at a cost of $664 million, and
a larger navigation lock was constructed in 1993. The total rated
capacity of both powerhouses is 1084 MW.
Construction of Bonneville Dam blocked the migration of white sturgeon
to their upstream spawning areas. Sturgeon still spawn in the area
below the dam and the lower Columbia River supports a harvestable
sturgeon population. Small, depressed populations of white sturgeon
persist in the various reservoirs upstream. To address anadromous
fish migration problems, the dam features fish
ladders to help native salmon and steelhead get past the dam
on their journey upstream to their spawning grounds. Elevation gained
up the Bonneville fish ladders is 60 feet (18.3 m).
For additional information and a fact sheet about Bonneville Lock
and Dam please visit the following site: http://www.nwp.usace.army.mil/Locations/ColumbiaRiver/Bonneville.aspx.