Same here with coming up Silver PlumeCo and it seemed it could have come from eavesdropping in on an email where I sent an out of state phone number. They called out of state if it came from my email. Not sure if someone can get a colorado phone number and not be from there.
Saw this number on my voicemail and was annoyed they didn't leave a message. Curious I googled the number and came across this website. According to my phone, call came from Georgetown, CO.