This is the situation that I am in. my sons mom has physical custody of him and she is saying that she can go anywhere out of state with him without getting in trouble with the law, is she right?

What does your child custody agreement say, get it out and read it.
Many have requirements that if they wish to move out of state, they will have to get the courts permission. Now if she is just traveling, or on vacation there is normally no restrictions unless it is interfering with your visitation time.

Where do you live?

this is the situation that i am in. my sons mom has physical custody of him and she is saying that she can go anywhere out of state with him without getting in trouble with the law, is she right?

She CAN go out of state without getting in trouble with the law. However, she cannot do anything that will violate a court ordered visitation schedule without permission from the court.

So you left out some very key pieces of info. Do you have a court ordered visitation schedule? Do you have joint custody (with her having physical custody)? By "go anywhere out of state", does she mean travel or does she mean a permanent move?

Please clarify so we can address the real issue.