I guess I'm the 1st person to inquire about this #, as it wasn't listed on this site yet.  I don't answer calls from unfamiliar #'s & if no message is left, I assume it's a spam call and block it.  This call came in on my cell, showing the 9 digit # and "Colorado" on caller ID.  I found an article about a 720 area code scam (http://99wfmk.com/scams/), so am definitely blocking this one.