ADOT is advising drivers and residents of Oak Creek Canyon that there will be an overnight closure tonight of State Route 89A. The closure is needed so crews can continue working on the State Route 89A Oak Creek Canyon Improvements Project, which includes rockfall mitigation, erosion control and bridge rehabilitation. Workers will close the highway northbound at the Cave Springs Campground and southbound at the Oak Creek Vista Overlook, which is the pull off just before heading into the canyon from Flagstaff. The closure will take place at 9 p.m. and run through 5 a.m. tomorrow morning. Drivers who use Highway 89A for their daily commute will need to Interstate-17 to the State Route 179 exit to get to Sedona and to Flagstaff during those times.