As an aside but relevent to the Op's question. How many gun ranges require proof of firearm license(in states requiring them), proof of a range safety class etc, or proof of being able to legaly hold, let alone own a firearm(felony convictions and such).
In Mass there are no public ranges, nor discharge or firearms on public land for target shooting(mostly). There are gun clubs, a closed to public state range, and a couple open to public pay ranges(license required).
I understand this is different in each state. I also understand shooting an airgun can be difficult with firearms being shot as well. Here's the rub. It's not any different shooting a firearm at a gun range with other guns being fired. You either get used to the report and carry on or don't.
The idea of shooting a pellet gun is that it can be done in your back yard. If you Airgun is too powerfull for your backyard it may be the wrong toy.
One more thing. To open an Airgun Only range for the public you will be required to follow the same process as a firearm range. It's EPA regs first, then anything else your state demands.
Good luck finding a place to shoot. Hopefully you can make friends with a farmer.