SoccerPOP, found this on the web, don't know if it also applies to SC:
Rule 2203. Olympic Development Program Player Tryouts

Section 1. Any player wishing to try out for the Olympic Development Program shall do so through the National State Association member of the State in which the Player may be registered under US Youth Soccer Rule 201.

Section 2. Any player released to play in another National State Association under Rule 201, Section 2 (a) may request, in writing, \ permission to try out for the Olympic Development Program in that National State Association.

Written permission must be received from:

the State Association where they are registered
the State Association where they wish to try out
Section 3. A player shall not be eligible to try out for the Olympic development Program in more than one National State Association Member territory. A player shall be responsible for all Olympic Development Program fees of the National State Association in which the try out occurs.