This is what I found but I haven't paid attention to HS wrestling in years so do not know if it's the current rules.
High School:
Overtime Scoring – A winner must be declared in all individual matches. If a match is tied at the end of
regulation, the following overtime scoring system is used in order, until a winner is declared.
• 1 minute sudden death period (first person to score wins).
• Two 30 second tie breakers (wrestlers swap referee’s positions). If match is still tied, it goes to a
ride-out.
• 30 second ride-out (wrestler who scored first has the choice in referee’s position). If wrestler
escapes from bottom position, he wins. If he is ridden-out for the 30 seconds, he loses.