What you heard was the Colorado Weather Net. They have been doing this for decades, it's actually a service to the National Weather Service that started in the 1950s, before the modern era of networked weather stations.
They still do give the reports to the NWS and they compile them into the daily climatic data you read on the web and stuff, even if it's not strictly necessary anymore. That's why you heard them giving the report number, the NWS can go back in their logs and match a station (which is a known location) and report to the day.
Incidentally, they are also on HF (80m I think) so that the outlying stations around the state who can't make the repeater on VHF can enter their reports.