Green’s Dictionary of Slang

(US) San Bernardino, California.

1914		H.H. Knibbs ‘Out There Somewhere’ in Songs of the Outlands 21: Around the world and back again; we saw it all. The mist and rain / In England and the dry old plain from Needles to Berdoo.
1927		C. Samolar ‘Argot of the Vagabond’ in AS II:9 387: Berdoo stands for San Bernardino, California.
1931		Irwin Amer. Tramp and Und. Sl. 163: San Berdoo.—San Bernardino, Calif.
1943		R. Chandler Lady in the Lake (1952) 92: The San Berdoo D.A. will likely want to talk to you.
1950		Goldin et al. DAUL 184/2: San Bardoo. San Bernardino, Calif.
1966		H.S. Thompson Hell’s Angels (1967) 20: Anything less would forfeit the spiritual leadership back to southern California to the San Bernardino (or Berdoo) chapter.
1973		Chopper Mag. June 46/2: The sissy bar — or goody bar as it’s called in Berdoo.
1985		O. Hawkins Chili 92: We’re headed toward the mountains above San Berdoo.
1988		New Internationalist June 🌐 San Bernardino, California, the year 1954. ‘San Berdoo’ is a rich boom-town of oddball bikers: the end of the road, transcontinental terminus for Route 66.
2004		posting at blogging.la 🌐 San Berdoo Fires 2004? Out in the San Bernardino Mountains yesterday morning, an arsonist thought it would be a good idea to set five fires.