I don't live in the us, but I'm planning my own jump, so maybe I'll be of some help here. I've been looking into places in nature (for sentimental reasons, but jumping nontheless) so you could see if there's a cliff, waterall, maybe a bridge nearby if you don't have access to a building.
I found this link in a replay on susa, don't remember which post tho, but it has some info on height and ground material, which may be of use.
Don't commit suicide without reading this site! Lost All Hope has information on everything from drugs and drop hanging to suicide statistics.
lostallhope.com
And there's megathreads for ctb methods, jumping has one too. although personally i find them somewhat cumbersome to sive through, there is a lot of useful information in the megathreads
