A few days ago I noted a piece of one of these debates on a TV channel at an early morning time and now see the video is linked to the Denver Post.  Hopefully I can find links to the five debates.

Listed as Part 1:

http://www.denverpost.com/electionshow/ci_26357938/watch-mike-coffm...

Listed as Part 2 of 5:

http://www.denverpost.com/electionshow/ci_26363898/mike-coffman-and...

Listed as Part 3 of 5, 08/20/2014:
http://www.denverpost.com/electionshow/ci_26368937/mike-coffman-and...

Listed as Part 4 of 5, 08/21/2014:

http://www.denverpost.com/electionshow/ci_26371144/aaron-harber-deb...

Listed as Part 5 of 5:

http://www.denverpost.com/electionshow/ci_26376330/aaron-harber-deb...

It looks like this is the web page to look for on the Denver Post:

http://www.denverpost.com/electionshow

I have no idea what television channel (4, 7, or 9?) I stumbled into at 4 or 5 a.m. one morning and caught the last few minutes of Part 5.  I typically do not watch any of those channels at that hour and do not subscribe to the Denver Post.  Hopefully the list will help others.