Master Sergeant Dave Baumgardner was a soldier, friend of Wyatt Logan, and his temporary replacement.
Dave Baumgardner was set to replace Wyatt Logan after his mission in the Alamo due to his inability to stop Garcia Flynn. He was brought to Mason Industries and was almost briefed about time travel's existence, but Lucy Preston and Rufus Carlin demanded Agent Denise Christopher keep Wyatt on the team. (“The Alamo”)
Later, Baumgardner did replace Wyatt after Wyatt stole the Lifeboat to try and prevent Jessica Logan's murder. Baumgardner was able to deduce that Charles Lindbergh was not killed by the crash site of his plane. Baumgardner brought an era appropriate gun on the mission, unlike Wyatt, who usually brought modern weaponry with him. Baumgardner was shot and killed on May 21, 1927 by Karl. (“The Lost Generation”)