Green’s Dictionary of Slang

beaver patrol n.1

also beaver hunt
[beaver n.1 (5) + SE patrol]

a group of young men looking for suitable female company.

[US]Current Sl. II:1 1: Beaver patrol, n. Girl watching.
[US]L. Dills CB Slanguage 9: Beaver Hunt/Patrol: looking for women.
[US]J. Ellroy ‘My Life as a Creep’ in Destination: Morgue! (2004) 128: The Beaver Patrol – USC frat boys fresh from late keggers.