UPDATE, 8:15 a.m.:
The northbound lane is of Nacimiento Lake Road at Mustang Springs Drive has been reopened, and the southbound lane will be open shortly, according to the Paso Robles Police Department.
Nacimiento Lake Road at Mustang Springs Drive in Paso Robles has been closed due head-on collision.
Emergency officials are asking drivers to avoid the area, as vehicles traveling in both directions will be diverted.
The crash was reported at 6:42 a.m. about one mile west of the Paso Robles District Cemetery, according to the CHP.
A large amount of oil was reportedly in the roadway.
It's unknown how long the road will be closed, according to Paso Robles police. Those heading south from the lake are asked to take San Marcos Road.