articleThe Brief Tohono O'odham police are on high alert, posting "No Trespassing" signs to keep federal border wall crews off tribal land this weekend. Tribal leaders declare trespassing a crime, but haven't specified how officers will handle federal workers caught on reservation land. What we know:Tribal officials put law enforcement on high alert Saturday after learning federal border wall crews might try to slip onto reservation property without permission. Big picture view:The tribe’s 62-mile stretch along the U.S.-Mexico border has become a central battleground in the federal border debate. Both sides are currently awaiting a ruling from U.S. District Judge Richard Leon on whether to halt federal wall operations permanently.