A split-rail fence or log fence (also known as a zigzag fence, worm fence or snake fence historically due to its meandering layout) is a type of fence constructed in the United States and Canada, and is made out of timber logs, usually split lengthwise into rails and typically used for agricultural or decorative fencing. Such fences require much more timber than other types of fences, and so are generally only common in areas where wood is abundant. However, they are very simple in their construction, and can be assembled with few tools even on hard or rocky ground. They also can be built without using any nails or other hardware; such hardware was often scarce in frontier areas. They are particularly popular in very rocky areas where post hole digging is almost impossible. They can even be partially or wholly disassembled if the fence needs to be moved or the wood becomes more useful for other purposes. During the American Civil War, these split rail fences were a major source of firewood for both the Union and Confederate armies.
Split rail fences were made of easy to split, rot-resistant wood. Traditionally American chestnut was the timber of choice until chestnut blight eliminated this tree. Currently, most split rails are made from cedar.
