There used to be OO scale in the US and it was relatively popular, but it has been supplanted by modern HO scale trains.
In the US, it seems that medium-sized scales declined into small niche-areas of the hobby,
as modelers on this continent shifted to smaller (Z, N, HO) and larger (O, 1:29, 1:22.5, and 1:20.3 large scales).
IMO, more people here need to experience OO.
If you don't have space in the garden for G scale, OO is typically up to the challenge for garden railroading.
Heck, apparently we can even have live steam in OO size!
That being said, all I was able to find was a contact for the NMRA OO SIG (Special Interest Group).
From the website:
3115 S. 11th St.
Tacoma, WA 98405
Maybe write to the address and see if he's still active?
Apparently this SIG prints a quarterly newsletter, so it may be worth a shot.
Other than that, there's very little left of OO in this country.
I've seen a few pieces of rolling stock and locomotives at train shows, but we're talking about 1 piece out of thousands for sale.
Hand laid track and scratch building could be done, but it seems that going with HO scale would save a lot of time.