Serving in Starfleet by 2153, Rivers was aboard Enterprise for its mission into the Delphic Expanse, at one point serving on the same engineering team as Crewman Jane Taylor. After Enterprise received devastating damage from the Xindi during the Battle of Azati Prime in 2154, Rivers was among the crew working to repair the ship and was confronted by Chief Engineer Charles Tucker III who had been suffering from a lack of sleep. (ENT: "The Forgotten")
After Enterprise returned home from the Delphic Expanse later that year, Rivers transferred to Columbia NX-02 under the command of Captain Hernandez, serving as an engineer aboard the ship. Prior to Columbia's launch, he was assigned by Chief Engineer Tucker to work with Strong in recalibrating the injector assembly in order to bring the Columbia's field matrix down to 0.3 microns. (ENT: "Affliction")
Rivers was played by famed cartoonist (and noted Star Trek fan) Seth MacFarlane in two cameo appearances. He was not identified by name until his second appearance. Some years later, MacFarlane created and starred in The Orville, an homage to Star Trek: The Next Generation co-produced by Brannon Braga.
In the final draft script of "The Forgotten", he was referred to simply as "a young engineer".
The Star Trek Customizable Card Game gives his first name as Stewart.