In the old days, when both automobiles and roads were few, motorists could easily get far enough from home to become lost. Although some named trails, such as the Cannon Ball Trail and the Yellowstone Trail, were marked in simple ways like yellow paint on roadside objects, long-distance travelers were usually guided by natural features such as hills, boulders, creeks, and rivers, or by landmarks such as bridges, barns, and schoolhouses. In 1917, engineers of the Wisconsin Highway Commission, with authorization from the Legislature, recommended and inaugurated the first statewide system for identifying highways by number. This road was designated State Trunk Highway 19, later U.S. 16, and was the first to be marked and signed by numerals. The familiar numbered highway system was later adopted by all other states and by many foreign countries.