<p>Since the Reaper Splitter in Siberia's biohazard container is over 10,000 years old, and the Lost Temple of T'hochek harbors a jade crystal artifact that was "ancient" in 1920, I think its probably safe to say humans earlier than the Colonel or spring-heeled Jacque had encountered Splitters. As far as the characters we know in the game though, the Colonel is probably earliest.
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