The largest volcanic eruption in recorded history occurred in an isolated part of Indonesia in 1815. The volcano, from Mount Tambora, ejected 30 more times the amount of ash than the eruption of Mount St. Helens in 1980. Although halfway around the world, Tambora's influence was felt throughout the northern hemisphere. Referred to as the year without summer, portions of New England and Canada experienced heavy snows and frosts throughout June, July and August. Tabora's volcanic dust clouds were relatively short lived, but 1816 was regarded as a famine year in Europe.
   While most volcanism occurs along oceanic ridges in the sea floor, Mount St. Helens reminds us of a potentially active line of subduction volcanoes in the Cascade Range. Three Fingered Jack is one of the oldest volcanic remnants in Oregon, heavily scoured by glacial activity. Its rock is extremely weak and crumbles easily, making mountain climbing here very difficult. The easiest and most popular route follows up the south slope where it was first climbed in 1923 by a half dozen youngsters.
   Originally named Mount Marion, it was renamed in the early 1900s. Its distinctive jagged ridge line, supported by a narrow north-south dike, emphasizes its complicated make-up. Named for a notorious desperado, Tres Dedos (Three Fingered Jack), the 7800 foot peak is made up of a series of radial dikes, plugs and cinder cones.
   Rising between Mt. Jefferson and Mount Washington, Three Fingered Jack is not the easiest peak to spot from Oregon's highways. Located near the Santiam Pass, these views are found on Route 22.

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