When I look at the Excel sheet after I downloaded and formatted the APN’s, it looks like there are a lot of duplicate APN’s but with different owners, specifically in Colorado. Why is this? How can I fix it?

The problem with this is rooted in Excel’s automatic conversion from ACSII delimited data to scientific formatting and then back to currency. To fix this, import the ASCII data from RealQuest into a .CSV file and NOT a .XLS file. Never convert to .XLS during the entire data dump to mailer process in Colorado.