The United States Department of Defense says live fire training ranges on Tinian in the Northern Marianas could support up to 400 U.S. Marines for 12 one week periods a year.
A final Environmental Impact Statement is now being reviewed by CNMI officials.
The Statement details the Department of Defense's buildup plans and analyses the impacts on Guam and the CNMI.
It estimates civilian use and access of the range training area would be affected for approximately 12 to 16 weeks each year.
Because training ranges on Guam are not enough, Tinian lands will have to be used.
The US Defense Department has a lease on the northern two-thirds of Tinian.