Approximately 54,000 U.S. personnel are stationed in Japan, with about half of those on Okinawa.
First Lt. Matthew Kraft set out on the solo ski trip Feb. 23 with an itinerary to complete a 195-mile trek.
Despite heavy rains, the $5 million project has progressed well and is about 51 percent complete.
San Diego and the Marine Corps signed a formal agreement Thursday to cooperate on advanced technologies.
The building known colloquially as "The White House" has been the command post of the 1st Marine Division since 1946.
On land, the Marines and soldiers set up mortars, secured the beachhead and entered a nearby town in patrols.
The training, which will continue through Feb. 15, builds on longstanding military ties between the two countries.
The National Museum of the Marine Corps visited Camp Pendleton to analyze and inspect historical artifacts of interest.
A retired Marine Corps combat veteran helped thwart a robbery in Pennsylvania on Tuesday .