Depending on the family’s overall financial situation, he might qualify for https://www.questbridge.org/ There is a sub-forum at the top of this forum just for Questbridge questions.
If he has a lot of civic and community work, he might qualify for good merit/need combos at colleges that participate in the Bonner Scholars program http://www.bonner.org/apply/ I know an Iowa farmer’s daughter whose profile looked a lot like your son’s (she did get her ACT up to 29) who was a Bonner Scholar.