US Topo maps are as accurate as the data sources used to make them, but because these sources are many and varied, it is not possible to make a single simple statement that the map as a whole meets a particular level of accuracy. US Topo maps, therefore, do not have a traditional accuracy statement in the map collar.

How accurate are contour lines?

Vertical accuracy, as applied to contour maps on all publication scales, shall be such that not more than 10 percent of the elevations tested shall be in error by more than one-half the contour interval.

How often are topographic maps updated?

US Topo maps are updated on a three-year production cycle (maps covering one third of the country are updated each year).