A resident found the baby boy in a dumpster around nine o'clock July 12 in the 1800 block of Oak Street.
Police believe the child to have been in the dumpster 5 to 6 hours. The child is at the Northwest hospital NICU.
Police arrested the mother, 21-year-old Shonnie Smalley, at 5 a.m. Sunday. She bonded out two days later.
She faces one charge of injury of a child, a 1st degree felony.