For reasons of economy, US Marines in certain specialties have long trained for specific skills at US Army bases. For instance, after Boot Camp, Marine artillerymen undergo instruction at the US Army Artillery Center and School (or whatever they call it now) at Ft. Sill, OK.
Likewise, as seen in this 2001 video, Marine tank crewmen trained at Ft. Knox. A lot has changed since then, but being a tanker will always involve a lot of hard, dirty work for the payoff of the fun of sending rounds downrange.
Especially moving is the reaction of the Marines when they learn of the World Trade Center attacks of 9/11.