UPDATE, 5 p.m.
Forward progress of the fire burning in the Nacimiento Lake area has been halted. The fire burned about 4 acres of woodland oak in the area of 5595 Aluffo Road before being stopped around 3:40 p.m.
Some Cal Fire crews were still at the scene, including five engines, two hand crews, a water tender and a helicopter.
There were no structures damaged, and no injuries were reported.
A cause has not been determined.
A 2- to 4-acre wildland fire is burning in the Running Deer Road area of Paso Robles.
All Cal Fire units and several other city fire departments, including the Paso Robles Fire Department, are responding to the fire near Nacimiento Lake.
According to Cal Fire dispatch, the fire is burning grass and oaks in the area of 5595 Aluffo Road. Preliminary investigation revealed no structures at risk.