How to find racial mirrors for your child

In researching transracial adoption, I have come to find that one of the most important things for a healthy identity development in a transracial adoptee is to find racial mirrors for the child. That is, children and adults who are the same race as the child who they can interact with regularly. My question is, how do you find racial mirrors? Especially if you do not already have friends of the same race as your child, or you live in an area that is racially homogenous.