The lease approved Monday includes a two-year option to MTSun LLC while regulators to conduct an environmental study.
If the company decides to proceed, the commercial lease will run for 30 years with an option to renew.
The board also approved a Helena land swap involving a former National Guard armory that has been closed since 2013 because of high lead levels.
The state will acquire a 25,000-square foot warehouse for its print and mail services in exchange for the armory and the former state liquor warehouse.
D&M Development plans to transfer the armory to the Montana Business Assistance Connection, which will eventually transfer it to Carroll College.