From the Ridge Route Preservation Organization:

Another wildfire has started at the south end of the Ridge Route in Marple Canyon along the 5. This fire, known as the Route Fire, has so far burned 250 acres and is not contained. The fire has burned across the old Ridge Route at the Callahan Line Change location, about 2 miles north of Castaic. Evacuations are underway as far north as Templin Highway. The fire has burned as far north as Martin’s, south of Templin Highway. It is not known if the structure survived.

At this time, I-5 is closed from State 138 to Castaic. The Ridge Route is also closed to through travel from Castaic to State 138 as the gates are closed. Do not use any portion of the Ridge Route as a bypass for I-5 at any time as it is not built for heavy traffic. Big rigs have attempted this in the past and got stuck, blocking others in.

For further information regarding road closures and detours, we strongly recommend Caltrans Quickmap at https://quickmap.dot.ca.gov/ which has detailed information and updated traffic conditions.

We will post updates, as needed, if the Ridge Route itself or historic structures are damaged or in danger. After the fire is out and things have settled down, we will assess any damage to the roadway and post a report.