A cattle grid – also known as a stock grid in Australia; cattle guard, or cattle grate in American English; vehicle pass, or stock gap in the Southeastern United States; Texas gate in western Canada and the northwestern United States; and a cattle stop in New Zealand English – is a type of obstacle used to prevent livestock, such as sheep, cattle, pigs, horses, or mules from passing along a road or railway which penetrates the fencing surrounding an enclosed piece of land or border. It consists of a depression in the road covered by a transverse grid of bars or tubes, normally made of metal and firmly fixed to the ground on either side of the depression, so that the gaps between them are wide enough for an animal's feet to enter, but sufficiently narrow not to impede a wheeled vehicle or human foot. This provides an effective barrier to animals without impeding wheeled vehicles, as the animals are reluctant to walk on the grates. Origins The modern cattle grid for roads used by automobiles is said to have been independently invented a number of times on the Great Plains of the United States around 1905–1915. Before that period, a similar device for railroads was in use at least as early as 1836; a stone stile was used in Britain as far back as pre-Roman times. An article in Texas Monthly claims that the "first recorded use of a cattle grid for nonrail traffic" occurred in 1881 in Archer County, Texas, on the stagecoach road between Archer City and Henrietta. Uses Cattle grids are usually installed on roads where they cross a fenceline, often at a boundary between public and private lands. They are an alternative to the erection of gates that would need to be opened and closed when a vehicle passes, and are common where roads cross open moorland, rangeland or common land maintained by grazing, but where segregation of fields is impractical. Cattle grids are also used when otherwise unfenced railways cross a fenceline. Cattle grids are common worldwide and are widespread in places such as Australia, the Scottish Highlands, or the National Parks of England and Wales. They are also common throughout the Western United States and Canada. In the United States, they are often used on Bureau of Land Management and Forest Service land, but are also used on paved roads and entry and