The Paso Robles Fire and Emergency Services responded to a report of a vegetation fire in the Salinas Riverbed around 3:30 p.m. Sunday.
The fire was burning in the riverbed near 3200 Sulphur Springs Rd., just north of the Highway 46 E bridge.
When firefighters arrived on scene, they found a 50 x 50 spot fire actively burning grass, brush and trash from an encampment.
According to fire crews, the fire was extinguished within in 15 minutes.
CAL FIRE SLO also responded to the fire.
The cause of the fire was determined to be human caused.