This Game should be done Outside.

game for a large group over a wide area

Identify the play area, which should be a large field or forested area.
Identify a Jail Space for captured scouts.
Divide the scouts into two teams.
Team A has 1 minute for its scouts to hide anywhere in the designated play area while Team B has their eyes shut.
A signal is given, and Team B spreads out, searching for hiding scouts.
When someone is found, he must be tagged - rougher versions require being tackled - to be captured.
Captured scouts are led to the Jail Space where they must stay - rougher versions allow captured scouts to attempt escape on the way to jail, but never once placed in the jail.
Once in jail, the scout can be rescued by having another scout on his team run to the jail area and tag him.
The Jail can have as many guards as the searching team wants.
The round is over when all hiding scouts are in jail. Then, teams switch roles and try again.