The following US places have a common property that no other US place can claim. Can you figure out what that property is? The answer is simple; it does not, in any way, require special knowledge or bizarre facts. I can imagine the possibility that I have mistakenly omitted as many as two places, though I very much doubt it. Such an omission on my part will not, in any way, hinder finding the solution. Don't bother guessing, you will know when you find the solution.

Alamosa, CO
Alma, CO
Chicago, IL
Colorado Springs, CO
Divide, CO
Denver, CO
El Paso, TX
Laramie, WY
Leadville, CO
Los Alamos, NM
Los Angeles, CA
Mammoth Lakes, CA
New York City, NY
Phoenix, AZ
Santa Fe, NM
Woodland Park, CO

The set of people who have independently solved this puzzle since I formulated it in 1995 = {}.

September 5, 2007 Note: This list is notably different from past lists. The two reasons for the differences are (1) I have mistakenly left off Laramie from recent lists even though it was on past lists and (2) properties change, note some additions and deletions relative to the previous list.