Apparently, there is a small strip of land in the Colorado Rockies that was not, by way of the errors o' cartography and surveying, included in any of the major land acquisitions. It took an act of congress to finally approve that this strip of land was part of the United States. Folklore has it that a condition of the agreement was that it would not be part of the US for a week every year. There is a festival in Summit county to celebrate this distinction; but I have yet to find complete verification of the story.

Remember, too, that Santa Fe, New Mexico is one of the oldest European settlements in the United States. The Spanish settled there in 1608 and were running around the area even earlier than that.