Franklin won individual races and paced a relay team to victory in helping the team capture the Class 5A state championship, The Denver Post said Sunday.
Franklin, a senior, said she will miss her high school teammates.
"Now, I realize why I did this," she said. "It's being with my girls for the last time. It's the very last swim with all of them and for me to have a Regis cap on my head."
Though not everyone was pleased with Franklin's performance. Some coaches and parents said they thought it unfair an Olympian was allowed to compete against high school swimmers.
She won the maximum eight individual events she was allowed to compete in and swam on four relay teams, all of which also won. Franklin set a national record in the 200-meter individual medley: 1:56.85.