A serious injury, multiple-vehicle crash has blocked the northbound lanes of State Route 347, according to the Department of Public Safety.
The accident is described as a rollover.
The collision was about three miles north of Maricopa, just north of Casa Blanca Road.
Drivers heading north are being directed onto Casa Blanca to Interstate 10.
The southbound lanes are open, but traffic is moving slowly and backup is lengthy while first responders provide assistance on the scene.
There is no estimated time to reopen the northbound lanes, according to the Arizona Department of Transportation.