Yellowstone, runabout (NX-74751)
An experiemental Starfleet runabout designed in part by Ensign Harry Kim in an alternate reality where he never served aboard the U.S.S. Voyager. This prototype (registry no. NX-74751) employed tetryon plasma warp nacelles. The craft was destroyed when Kim used it to return to his original timeline.
Not to be confused with the Starship Yellowstone.