I agree with the above. At least in my state, school districts are required to have Gifted Education coordinators, which was the obvious place for us to start. They had well defined processes for gifted evaluation, annual Gifted Education Individualized Program creation, etc. The program was not widely publicized, but when our kids qualified they were very good.

Sadly, I've heard that it's much more challenging in some areas, so read up on the laws and all of the resources here on Parent Advocating.