Sure, if you are certain you want to use the log files to capture data, then regardless of whether or not you want to maintain seperate files or not, you can change how much data is kept.
In the "Log to File" action endable log file rotation and configure the settings to your preferences.
You should be able to see up-to-date logs in one of the files though... Why it's only recent up to March 1st would tell me that either you're looking in the wrong file or your servers aren't logging.