I talked to Steel Challenge and they said they only list major matches. Now, having said that I have had best results finding matches by google searches. I put in the largest city name, steel challenge, practical shooting, range. Then email the contact person on any pertinent web sites. If your search returns a IDPA club, email and ask about steel, if it returns a rifle match, email and ask about steel challenge in the area. My best intel has come from other shooters.
I hope that helps.