The Twenty Mule Team

Flickr user Caveman 92223 posted this interesting old photo of the historic twenty mule teams used to haul borax from the mines to the railway back in the late 1800s, in Death Valley. The history of the  mule teams can be found on Wikipedia. They were famous in their day due to the enormous size of the wagons and weight of the loads; both the drivers and mules worked in extreme conditions.