Yeah, it sucks, I live in the states and would only punt when I went to Asia, and that didn't work for references back here! So, what's a guy to do?
Well, first, you can sign up for a service like:
https://www.preferred411.com/P227314 <- example girl from Chicago area!
I personally have made heavy use of The Erotic Review:
https://www.TheEroticReview.com/
I'm VIP on here (earned through reviews), and that helps tremendously!
There are also Ad & Discussion boards on the TER so you can always poke around those for intel.
Depending on where you are in the US, there are different sites that work. CityVibe tends to be good on the west coast, and AAMPs seem to be more Newbie Friendly. If you are in NYC, there are lots of AMPs that offer FS, and I've never had much problem getting in them, although that is starting to change.
My suggestion is just search through TER and find some providers you like, then call them up.
Start to build up your US Profile, post reviews on TER so next time you can point to your account there.
You can always try sites like WhatsYourPrice, SeekingArrangement, etc. I've not tried them, but others on here have posted positive experiences.
Feel free to ask questions, I'm sure people can help with specific cities (I recall seeing someone just posting something on LA the other day). I recall the poster mentioning that WeChat is pretty good in LA.... maybe other cities as well?