"...A travois (trævwɑ) is a historical frame structure that was used by indigenous peoples, notably the Plains Aboriginals of North America, to drag loads over land. The basic construction consists of a platform or netting mounted on two long poles, lashed in the shape of an elongated isosceles triangle; the frame was dragged with the sharply pointed end forward. Sometimes the blunt end of the frame was stabilized by a third pole bound across the two poles.
The travois was dragged by hand, sometimes fitted with a shoulder harness for more efficient dragging, or dragged by dogs or horses (after the 16th-century introduction of horses by the Spanish).
A travois could either be loaded by piling goods atop the bare frame and tying them in place, or by first stretching cloth or leather over the frame to hold the load to be dragged.
Although considered more primitive than wheel-based forms of transport, on the type of territory where the travois was used (forest floors, soft soil, snow, etc.), rather than roadways, wheels would have encountered difficulties which would have made them less efficient. As such the travois was employed by coureurs des bois in New France's fur trade with the Plains Tribes.
It is possible for a person to transport more weight on a travois than can be carried on the back..." *
Historically, variants of the Travois Stretcher have appeared throughout history. Lewis and Clark, while following an ancient road that connected the Walla Walla and Columbia rivers to confluence of the Clearwater and Snake rivers, found it easy to follow the parallel ruts left by travelers employing travois stretchers to move their belongings and trade goods. The illustration at the top of this post show that both horses and dogs had the task of helping their owners carry the load when migrating on the plains.
This video, while not created specifically for trekkers, does give very clear instructions on how you could make your own travois stretcher. Perhaps one of you might make a travois for your dog to help him carry your snacks on the next trail walk!
* From Wikipedia. Original post can be found here.