I have been playing this game for a little while now and all I can say is I love everything about it. The 90s vibe, the UI, the music, and the way you're expected to decode the mystery.  I'll come back to edit this comment and rate once I've finished, but I just wanted to let you guys know I am thoroughly enjoying your entry.

EDIT

I just completed the game. Got almost perfect solution and I loved it. I must say The Rivergrove Files is one of the best indie games I have ever played. It feels like a professional title, from the UI to the radio station and the music. The mystery is interesting and well integrated with the theme of the jam. The game is really polished, I found no bugs. Deep down it's all about reading text, but it doesn't feel like that in any way. Hats off to you for achieving all this in such a short time frame!!!

Some minor points in case you want to go commercial (I gather you do from the Wishlist on Steam icon on the desktop) :

• I ended up compiling my own timeline on a Word file, as I felt the in-built timeline was kind of cumbersome to fill out (although absolutely necessary and useful for gameplay). Maybe it would be worthwhile re-thinking this part of the game.
• It took me about four hours to beat the game. Not sure there is a save-load function. If there is one, I couldn't find it; if there isn't, I think this game would definitely need one to avoid losing your timeline every time you have to stop playing (my own entry to this game does not have one, but I think it's much shorter than yours).
• I think the use of hyphens in phone IDs was inconsistent a couple of times. I know because I had to note down the numbers exactly as they were on a piece of paper before transferring them to the automatic matching system, which wouldn't work for this reason. This set me back a little. It was nothing major, but I just thought I'd let you know. I think this happens at least with the phone found by the river.
• Implementing cut & paste would contribute to streamline the bits where you need to transfer info from the files to the interactive parts of the UI.
• The 98-99 feels almost unfair. I only realized by chance that this was "a thing". So you really need to pay attention for the events to make sense. One mistake with this is what ultimately led me to miss out on a perfect score.

As I said, though, this game reminded me of why I love playing indie games. Thanks very much for making it, and please, keep up the good work!!! :D :D :D