I found a Kim Zappia with the phone number 970 388-3336.  She is also bragging about her investigation ability on LinkedIn.
I also found a law company that deals with harassing debt practices and they say that a debt collector has to inform you that this is a note from a debt collector.  
I got one of these notes today and did a search on 970 388-3336 KIM and that is how I got the information I provided in this reply.  A basic search came up with this info.
Kim Zappia  Owner of 24 Hr. Legal Process Service & Private Investigations.  Maybe a class-action law suit is in order.

Got the same message taped to my door today to.o

Same message on my door.  Called her back but there was no answer so I left a message

Kim is handles civil litigation cases so someone is trying to sue you over money. I only have to debts one from stupid college America who have been harrasing me for 12 years and the other is Davidson's property's out of colorado springs. However kims process server techniques is just wrong she pounded on my moms windows at her house and has now found mine posting little papers and threatened me with the sheriff's on a sunday if anyone else has these debts let me know im not about to call her

Yes they do im thinking of changing my number they call so much