The Effingham County Industrial Development Authority and OmniTRAX, a private railroad and transportation management company, announced Friday that they have formed a partnership to develop the 2,600-acre Research Forest tract in Rincon. OmniTRAX will spend from $85 million to $100 million to build a road and utilities, making the property useable soon by industries large and small that want rare, dual-rail access close to the Savannah port, international airport and interstates. It’s the biggest deal the IDA has brokered since the authority was incorporated in the 1960s, according to IDA CEO John Henry, creating a megasite and bringing the potential for thousands of jobs. The deal means the IDA will recoup the $30 million it has invested in the land and will not have to spend any tax dollars for infrastructure to make the tract useable. After the IDA gets its $30 million back and OmniTRAX recoups the money it invests in infrastructure and land, the profits from land sales will be split 50-50. The land is worth an estimated $300 million once the infrastructure is built, Henry said.