|The following is based on Van Buren and is not canon.|
First, the escort traveled to Denver, but the soldiers got bored there, so they left. They were the team accompanying Goddard when he discovered the Boulder Dome around 2247. However, after Victor Presper decided to relocate to the Dome, Larsen's team traveled to the Hoover Dam with Goddard to settle down. Of course, they were paid for their services. Then, in 2250, they traveled with Goddard, Agnes, and the Galenski's back to the Dome in hopes of reclaiming it from Presper and his military team.
Once there, Presper left, having accomplished what he came there for. There-in, Larsen and his soldiers became the guards for the scientists in the Dome.