Travel Reference
In-Depth Information
obsidian in the rock. Crawfish Creek is named for the small freshwater crustaceans, same as
crayfish or crawdads, that thrive in its thermally warmed water.
The long, gradual ascent of the road beginning here takes you up the southern flank of the
Yellowstone Caldera.
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South end of Lewis Canyon. Fire damage that begins just north of here is from the
1988 Snake River complex of fires. You can still see where the fire crossed the canyon and
burned down into it.
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An interpretive sign about the 1988 fires.
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Best overlook of several possible ones (only usable when going north) at the north
end of
Lewis Canyon [GEO.10].
Don't stop on the dangerously soft gravel shoulders along
here—use the areas with widened pavement.
Moose Falls rushes over hard lava toward the Lewis River.
The rocks you see across the canyon near the tops of the cliffs are Lava Creek tuff, part of
the vast eruption that formed the Yellowstone Caldera 639,000 years ago. The Lewis River has
cut down through these easily eroded rocks and is now exposing older lavas at the bottom of
the canyon. Younger rhyolite lavas are west of the road. (For more about the caldera, see “The
Yellowstone Caldera” in the Geological History chapter.)
