A log flume generally refers to one of two things: either the literal device used to move logs from one location to another, or the common amusement park ride based on the same concept. Flumes are generally any sort of artificial construct intended to move water from one place to another, and are often used in dams. A log flume, however, moves water incidentally as a transport medium for fallen timber logs.
Actual log flumes are now considered to be a relic of the past, with roads and timber trucks largely having replaced them in the modern logging world. At one time, however, the log flume could be found in a handful of countries around the world, but nowhere as ubiquitously as in the United States. Lumbermen of 19th century America built monumental log flumes to transport logs for miles where there were no suitable rivers to use, and where the terrain was too rugged to build a railroad.
The earliest log flumes were built in the mid-19th century, and were essentially square chutes of wood raised up above the terrain. These chutes would be filled with water diverted from a river or lake, and logs would be sent down them. The design, however, had a major flaw: if a log became jammed in the chute, it would cause a total dam, with other logs becoming stuck. Eventually, the water would start pouring over the edges, and the entire log flume would be destroyed. As a result, this type of log flume could be used only for short distances, where workers could watch for jams, and free them quickly.
In 1868, James W. Haines created a V-shaped log flume to replace the earlier square-sided design. The V-shape meant that if a log got jammed, when the water level rose the log would rise up to a wider chute, and would free itself. Suddenly, length was no issue, and log flumes in excess of 60 miles (97 km) long sprang up throughout the great timberlands of the Pacific Northwest.
Perhaps one of the greatest log flumes ever constructed was the Kings River flume, build in 1889. Built to service the more than 30,000 acres of prime redwood timberland owned by Austin Moore and Hiram Smith, the Kings River flume traveled 54 miles (87 km) and dropped more than 4,000 feet (1,220 m) on its journey. Logs were actually cut in a mill before being placed in the flume, then tied together into bundles, which were in turn linked into chains by "flume herders" along the way, who worked with large poles. These chains of logs could be nearly 1,000 feet (305 m) long, and weigh tons.
Even after the log flume vanished from the wilds of America, it lived on in the popular consciousness. Amusement parks throughout the world constructed their own versions of the log flume for visitors to ride on. These rides generally consist of an artificial waterway and some sort of vehicle, often shaped to look like a piece of a tree. Passengers ride through the water, and occasionally climb to a high point to plunge down quickly into a body of water, making a large splash.