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Tumtum Mountain

Pleistocene lava domesVolcanoes of Washington (state)
Tumtum Mountain West View
Tumtum Mountain West View

Tumtum Mountain is a small, highly-symmetrical volcanic cone in Washington, United States. Located in northern Clark County at the easternmost end of Chelatchie Prairie, it rises to an elevation of 2,004 feet (611 m), about 1,400 feet (430 m) above the flat prairie. This Pleistocene dacite lava dome is part of the Cascade Volcanic Arc, and with an age of only about 70,000 years, Tumtum Mountain is the youngest and westernmost volcano in the Cascades of Washington state.

Excerpt from the Wikipedia article Tumtum Mountain (License: CC BY-SA 3.0, Authors, Images).

Geographical coordinates (GPS)

Latitude Longitude
N 45.93414 ° E -122.33695 °
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Clark County



Washington, United States
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Tumtum Mountain West View
Tumtum Mountain West View
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Yale Bridge
Yale Bridge

The Yale Bridge or Lewis River Bridge spans the Lewis River near Yale, Washington. It was built in 1932 by Cowlitz and Clark counties. The suspension bridge has a clear span of 300 feet (91 m), with a total length of 532 feet (162 m), replacing a previous steel truss bridge at the site. Construction of the Ariel Dam had created Lake Merwin with a water depth of 90 feet (27 m) at the site, requiring a new bridge that did not need to have support piers in the water. The road deck, stiffened by a steel Warren truss, is 50 feet (15 m) above the high water line of the reservoir.The bridge was designed by Harold H. Gilbert of the Washington State Highway Department, and was constructed by the Gilpin Construction Company of Portland, Oregon. The only short-span steel suspension bridge in Washington, the bridge incorporates unique features. Only the central span is slung from the cables, with separate unloaded cables acting as backstays running from the 88.75-foot (27.05 m) tall towers to concrete anchorages in the canyon's rocky sides. The approach spans were originally supported from below by a timber structure. The cables are discontinuous at the towers, unlike most suspension bridges, in which the cables run over a saddle on the towers. With less wear, the cables could be smaller. The bridge deck is made of timbers with an asphalt overlay. The counties transferred the bridge to the Washington State Department of Highways in the late 1930s and it was refitted in 1957–58 with steel approach spans. It is noted for prominent brackets supporting osprey nests.The bridge was placed on the National Register of Historic Places on July 16, 1982.