Witnesses told officers that Destiny Ahenakew, 25, took out a bible and prayed before she threw the toddler.
Police arrested Ahenakew on Saturday and booked into jail for First Degree Assault of a Child.
Court documents stated that Ahenakew told a witness "the devil made me do it."
Witnesses told police that they saw Ahenakew swing her son twice before she tossed him down the hill near W. Mission near N. West Point Road. Officers said the boy fell 50 feet. He was stopped by a pine tree according to witnesses Saturday afternoon.
One of the witnesses said Ahenakew and her child approached him and asked for some water prior to the incident. After he provided them with water, he called police because he said he was concerned that they had nowhere else to go. Then, he said he saw the mother throw the toddler into the air and over a fence.
Another person at the scene was able to get the child and bring him up the embankment to safety.
Officials said the child was taken to the hospital with non-life threatening injuries. By Monday, the boy was out of the hospital. Child Protective Services had released the boy to family members.
Ahenakew has had previous run-ins with Spokane Police Department but nothing related to violence.
She faced a judge Monday afternoon. Ahenakew's bail was set at $50,000. Prosecutors asked that if Ahenakew does make bail, it should be mandatory that she cannot use methamphetamine.