Inspectors determined that four girders were damaged after a big rig carrying construction equipment collided with the overpass last Thursday.
Three of those will need concrete patching which starts this Saturday through Sunday from 6 a.m. to 8 p.m.
One lane and the off-ramps will be open at that time.
On Oct. 27 crews will reconstruct another damaged girder which will require closures to northbound Highway 99 at Applegate Road from 9 p.m. until 5 a.m.
That should last until November 10.
Traffic on the overpass will be closed during the repairs.