Brown Material Road is a 5.2 mile stretch of unremarkable roadway between Highway 33 and Highway 46 in Kern County California. While it's a name that invites speculation as to why it would be called Brown Material, I could find no real reason for the name.
However, the area around Brown Material Road is very interesting. Highway 46 about 30 miles west of Brown Material Road is where James Dean was killed while driving is Porsche Spyder.
The State of California designated Highway 33 through Kern County as "The Petroleum Highway." Highway 33 passes through the Midway-Sunset Oil Field. Which is the largest oil field in California and 3rd largest in the United States.
The Midway-Sunset Oil Field is about 4 miles wide and 20 miles long and Highway 33 passes through the most heavily developed part of the oil field. The oil field has been in production since 1894 and has produced 3 billion barrels of oil.
I find the southern part of Highway 5 in the San Joaquin Valley, to be deadly dull. So I usually take Highway 33 at Coalinga. It's a lot more interesting and it's got Brown Material Road.