The Adirondack Live Steamers in upstate NY are having our Spring Meet this weekend. We have 1.5 miles of mainline down, plus probably that amount in sidings and yard tracks. Don't know the mileage on the Brick Mountain Railroad, but we are one of the largest in 7.25" gauge (but not 7.50" gauge).
What I meant was largest private. Many of my Brethren at the Pioneer Valley live steamers have been up your way for a visit. I would like to someday also