Lieutenant Jadzia Dax takes a Trill initiate Arjin on a trip through the wormhole and back in the Mekong. During the flight, the runabout ran through a subspace interphase pocket. The runabout's starboard nacelle snagged a piece of what was first referred to as "subspace seaweed" but was later discovered to be a protouniverse. (DS9: "Playing God")
In late-2370, the Mekong was fitted with additional photon torpedoes and accompanied the USS Odyssey into the Gamma Quadrant in an attempt to rescue Commander Benjamin Sisko, then a prisoner of the Dominion. (DS9: "The Jem'Hadar")
In 2371, returning from consultations at Prophet's Landing, Major Kira Nerys and Odo detected a Maquis attack in progress. They pursued the attacking ship in the Mekong but due to prevailing conditions, the pursuit took them down to the surface of a moon with an atmosphere that was impenetrable to the runabout's sensors. (DS9: "Heart of Stone")
Later in the same year, Odo and Elim Garak took the Mekong to the Unefra system in search of Enabran Tain. (DS9: "Improbable Cause") They located him, but were subsequently captured by the warbird commanded by Lovok and Tain, and sequestered in the warbird's shuttlebay on "E" Deck, Section 25. The runabout was then carried into the Gamma Quadrant. The Mekong was abandoned after Odo and Garak, attempting to escape the Battle of the Omarion Nebula, were beamed aboard the USS Defiant. At the time, the Mekong's warp drive and shields were offline, and main power was failing. (DS9: "The Die is Cast")
|Danube-class: USS Gander • USS Ganges • USS Mekong • USS Orinoco • USS Rio Grande • USS Rubicon • USS Shenandoah • USS Volga • USS Yangtzee Kiang • USS Yukon • NCC-73918 • Unnamed|
|Yellowstone-class: USS Yellowstone|
The Star Trek Encyclopedia listed two registries for this runabout: NCC-72617 in the main entry and NCC-72917 in the starship chart. The registry was seen briefly, yet not clearly, in an okudagram in "Whispers". The Encyclopedia also noted that the ship was named after the eponymous river in southeast Asia that flows south to the China Sea. (3rd ed., pp. 296, 473) In the latest Encyclopedia (4th ed., vol. 2, p. 332), NCC-72917 was changed in the chart to NCC-72617.
Also according to the Star Trek Encyclopedia (4th ed., vol. 2, p. 33), the Mekong was destroyed in the aftermath of the battle in 2371.