USGS 7.5-minute Traditional Topographic Map Series of 1,071 sheets portrays the physical and cultural details of Illinois. Their large scale, 1:24,000, permits detailed and accurate display of natural and man-made features. The 1:24,000 scale means one inch on the map represents 2,000 feet on the ground. Physical features, such as hills, valleys, plains and other relief, are shown by the brown contour lines that connect points of equal elevation above sea level. Water bodies appear in blue and wooded areas have an overprint in green.The maps show many cultural features, including cities, towns, villages, and smaller populated places as well as highways, trails, railroads, pipelines, power transmission lines, dams, and airports. In rural areas, individual buildings are shown. Each quadrangle map covers a block of Illinois that measures 7.5 minutes of latitude by 7.5 minutes of longitude. The area of the quadrangles ranges from about 55 to 57 square miles, depending on its location in the state. Popular with outdoor enthusiasts, these topographic maps can help make hunting, fishing, hiking, cycling, and other outdoor activities in Illinois much more interesting and enjoyable.