For those in the North East, New Jersey has two ranges where you can shoot out to at least 300 yards, has real stable (concrete) benches, covered shooting positions etc.
Central Jersey Gun Club is one, which is kind of between the Jersey Shore and Trenton in Franklin, New Jersey and Cheery Ridge up near Franklin Lakes.
To be able to join Cheery Ridge, you have to attend an orientation session given on the first Sunday of each month. I will be taking this on August 7th, and plan to join the club that day.
There are 100 yard Benchrest matches shoot there in the summer including Factory Class in the morning and Heavy Varmint in the afternoon.
During the winter Central Jersey has a 100 yard Benchrest league.