To me, this is one of the iconic symbols of the western United States. The cattle guard. Where in Iowa and Nebraska, most livestock are fenced and most pastures are gated...livestock in Wyoming, Colorado and Montana (and other western states) are restrained by both barbed-wire fencing and cattle guards like this one. A simple grate that prevents cloven hoof animals from wandering off the rancher's range. Many interstate off-ramps end in a gravel road guarded by grates such as this one. Oh, and please do keep out. That's why I shoot lots of stuff with telephoto lenses. If you travel west, please honor the rancher's property lines...your respect to the land is appreciated.