In 1861 Congress appropriated an additional $100,000 in order
that John Mullan might reroute a portion of the Mullan Road in
northern Idaho. The original route swung south of Lake Coeur
d'Alene, but flooding hazards on the St. Joe River threatened
the potential use of this section. The new portion of the road,
north of Lake Coeur d'Alene, was heavily timbered and, as a
result, Mullan and his crew found themselves in what is now
known as Fourth-of-July Canyon on Independence Day, when they
were scheduled to be at the Coeur d'Alene Mission, the
intersection point with the older road. It was on this day that
the Mullan Tree, a white pine, received its inscription "M. R.
July 4, 1861." The M. R. stands for Military Road, initials with
which Secretary of War Davis had instructed Mullan to mark the
trail at frequent intervals. Mullan apparently did not think
this an unusual occurrence, because his "Report on the
Construction of a Military Road from Walla Walla to Fort Benton
"does not include any specific reference