You can buy traps at some tractor supply stores and feed stores, or off of the internet...or make them yourself (easy to do). then put popcorn inside to get them to go in...places to set them are private building where you get permission (again, feed stores or near grain silos and such) so people won't mess with them. One other way to get them is if you see them in parking lots (for some reason they frequent the Wal-Mart parking lot near where I live). go there on an "off day" like a Sunday morning, and use a big salmon net. lay it flat on the ground and put popcorn in it and stand/kneel next to the handle of the net. When the group of birds step in then flip the net over quick! Pick them up and put them into crates in the back of your truck...when/if someone ask just say you're helping to "re-locate" them as they are too many and they make a mess...you could try a county or city park but that's public property and they might frown or even have local ordinances about not feeding the birds, parking lots are often private property and you might get asked to leave but highly doubtful as those birds *censored* on everything and most stores hate them as they nest in vents and such.
I see your in the Tri-Cities...maybe near some grain silos, hay fields, hay stacks, etc....I am sure some farmer wouldn't mind you getting the out of their barns or off of their hay stacks since again, they *censored* on everything!
Good luck!