Hog Wallows that Are Not HOG Wallows

I find hog wallows fascinating and irresistible because they are unusual, and their cause is debated. They have been preserved for us by the Buckman family of Exeter marked by a Tulare County Historical Society marker in 1979.  

Historic Spots in California:  5^th Edition briefly describes the phenomenon of hog wallows and records a history of their origin and the demise.  “The Yokuts Indians believed they were leftover earth dumped from work baskets after the building of the great Sierra Nevada. (p. 540).”  Another early theory was that they were formed by pressure from escaping water and gas. Still another idea attributed the hill building to local gophers. (Ibid. p. 540). 

Courtesy of Tulare County Library

The earliest scientific article I found about Hog Wallows was written in the 1877 article, The “Hog Wallows” of California by Alfred R. Wallace quoting an 1874 article by Prof. Joseph Le Conte in the American Journal of Science p. 366.  They both credited “surface erosion” as the culprit for creating the mysterious mounds, but Wallace observed that the areas covered by hog wallows have the unique attributes of being treeless and having  “a moveable” surface soil covering a “less moveable one” below.  Wallace stated that the surface is eroded down to the pebble layer in places leaving elliptical shaped mounds that vary in size, but average 5 feet high by forty feet in diameter.

Hog wallows were removed with the help of the Fresno Scraper, first patented in 1882, to make the fields ready for agricultural purposes.  When tractors were added in 1910-1920, the scraper become even more efficient, and “laser beam controlled scrapers have also reduced surveying and operator skill requirements for land leveling for agricultural and construction.