Locally based Monarch Beverage Co. plans to transform a vacant drive-in theater in Lawrence into its new headquarters. The theater would be replaced with nearly 1 million square feet of new office, warehouse and distribution space under plans filed this month. The stateâ€™s largest beer and wine distributor has outgrown its home along Interstate 465 just east of the airport and has been looking for new digs for a year. IBJ first reported Monarch’s interest in the Lawrence site in a story last month. Monarch plans to spend about $45 million on the new facility, which would serve as a home base for more than 600 employees. A site plan shows a first-phase of 510,000 square feet and a second-phase of 450,000 square feet. The 93-acre site, along Pendleton Pike just east of Post Road, has been vacant since 1993 and once was targeted for a horse-racing track. It is owned by Estridge Development Co.