The King County prosecutor's office wants to try them as adults on assault charges in the attack that knocked a staff member unconscious.
A judge will be asked in two weeks to decide whether to move their cases out of juvenile court.
All six of the 14- and 15-year-olds also are charged with escape for the breakout Saturday near Snoqualmie. They were caught after a helicopter spotted them hiding in brush.
The three who are facing only the escape charge are due in juvenile court Thursday.