Re: build your own private range
Better have a good gate and lock. Change the lock and key each membership period. Cheaper than the alternatives.
Insurance, talk to the NRA about how to structure this, they have a department set up for precisely this sort of thing, even including range construction/upgrade subsidies/grants. Yeah, the NRA wants money. This is one of the things they really like to use it for. Wise up; for things like this that advance the sport of shooting, that encourage safe firearms usage, they are truly your best friend.
Bulldozers are nice, but parallel berms are kinda like mosquitoes and sledgehammers. There are more efficient ways.
A good one is safety baffling around the firing point. If you've ever seen a pergola, you understand. A framework of lumber set up not far above the bullet path will limit upward bullet angle, and the same thing on the sides will limit sidewards bullet angle, and it's a lot easier to provide (and maintain) than berms. It can serve as a defense against claims about wild/stray rounds striking property. With effective baffling, most of that schtuff is patently impossible.
Lumber is cheaper than lawsuits; use plenty.
Do it right, and it also cuts down on noise escaping from the firing line (another, not small, issue). Shrubbery (like Balsam Fir) and fast growing trees (like Lombardy Poplar) surrounding the firing point on three sides will go a long way toward sound reduction. A firing lane lined with such growth will also cut down and redirect reflected muzzle blast. Sound should go only one way, up.
When establishing the facility, invite local law enforcement down to examine, advise, and use the facility. Propose that a section be reserved and configured to support their training activities. It's the right kind of relationship to be cultivating; and honestly, any other approach is just dumb. Never, never, never, ever, ever, ever treat LE as an adversary.
Greg