46 University of California Publication in History

sending of an official protest to Onis. In the latter year another
group under Robert McKnight was captured, and they were not
released until 1821.
 Similar difficulties developed during the Adams-Onis negoti-
ations. A boundary argument arose over the activities of Joseph
Philibert, Jules de Mun, and Auguste Pierre Chouteau, who set
out for the Southwest in 1815. After a cordial reception in Santa
F6 and a winter's trapping on the east slope of the Rockies, they
were haled before Governor Pedro Allende, who maintained that
they had been working in Spanish territory. Philibert countered
with the assertion that Louisiana included all the area to the
Rockies. The Spanish governor, invoking the Spanish theory that
the Louisiana Purchase was illegal, declared that Spain still owned
to the Mississippi. The men were ultimately released, but only
after their goods had been confiscated. This affair also caused a
diplomatic controversy, resulting in a claim by the State Depart-
ment against the Spanish government, which was not settled until
years later."
 It was apparent that the frontier, though undefined, followed
 the general course of the Rockies, from the head of either the Red
 or the Arkansas River to some point north of the region occupied
 by the Spaniards. This left a huge area, little known or exploited,
 between New Mexico, California, and the Oregon country-a high
 region of mountain and desert, to which the United States, in its
 westward expansion, had not yet sent its scouts, and which lay
 vaguely within the realms of King Ferdinand.
 Across from New Mexico to California, through Arizona, a way
 had been opened by Father Francisco Garces, in 1775-1776. Far-
 ther north the only notable enterprise had been the pathfinding
 tour of Fathers Francisco Dominguez and Silvestre de Escalante,
 through what is now southern Colorado into Utah, and down into
 Arizona, instead of across the Sierra as planned.
 From the few expeditions and from conjecture, some rather
 vague ideas of the geography of the region had developed. One
 interesting example was the idea of a river running from the Salt
 Lake to the Bay of San Francisco." However, little conception of a
 boundary existed, and above the Arkansas the vastness of the un-
 explored mountain and plains area made international conflict of
 interests of rare occurrence.