FROM THE FRUITA INTERCHANGE on I-70, the overpass
leads north into the town of Fruita, and Colorado Highway 340 leads
south about 2-1/2 miles to the West Entrance of Colorado National
Monument. One mile south we cross the new bridge over the Colorado
River; the old bridge formerly connecting Fruita with the Monument may
be seen half a mile upstream. Just south of the new bridge we see
sandstone on the left and green shale on the right, both part of the
Burro Canyon Formation. The high hill on the left is made up
of brightly colored siltstones and
mudstones of the Brushy Basin Member of the Morrison Formation capped by
the basal sandstone of the Burro Canyon Formation. On the southeast side
of this hill is another bronze plaque set in a masonry monument, similar
to the one at Riggs Hill (fig. 39), commemorating the discovery and
removal in 1900 by Elmer S. Riggs of a skeleton of the immense dinosaur
Apatosaurus excelcus Marsh. (See figure 23B). About 1-3/4 miles
northwest of the new bridge is the Fruita Paleontological area discussed
on page 50.
Just south of the hill, the highway curves gently to
the left across a relatively flat surface of the Morrison Formation. To
the right may be seen good exposures of the Entrada Sandstone, at the
north end of which curbstones were quarried from thin beds of the white
Moab Member for use in some of the parking areas along Rim Rock Drive.
Some of the beds are ripple marked31 from wave action along
ancient beaches or within ancient lagoons. Some ripple-marked curbstones
from this quarry may be seen in the parking area at Red Canyon Overlook,
and elsewhere in the Monument.
31Lohman, 1965a. p. 44.
As we approach the Monument we see that to the left
the rock strata are bent downward toward us along what geologists call a
monocline (see figs. 27 and 30), but to the right may be seen cliffs of
dark Proterozoic rocks surmounted by slopes of the red Chinle Formation
and cliffs of the buff Wingate Sandstone capped by the lowermost beds of
the resistant Kayenta Formation. The bent and broken
rocks ahead are well shown in figure 33.
About 1-1/2 miles south of the Colorado River we reach
the T intersection noted previouslyat the end of the trip from
Grand Junction through The Redlands to the West Entrance of the
Monumentand we are ready for our trip through the Monument.
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