October 19, 2017 - Independence Rock and the Sweetwater River on the Oregon Trail in central Wyoming.  The wagon trains from Missouri were supposed to reach this rock by the Fourth Of July to insure they were on schedule to pass over the Rocky Mountains before winter.  Hence the name Independence Rock.  Most of the dates on the rock are in July.  Notice the close correlation between the historic sketch and the next (final) photograph from the top of the rock.