Contours can be extracted from thetopographic map at the resolution of your choosing. Contours can be exported to a variety of formats including shapefile (.shp) and drawing (.dxf). Digital elevation models (DEMs) are also available.
Contours can be opened in AutoDesk Civil3D (or similar) simply by opening an dxf file or shapefile exported from Equator. This tutorial explains how to create a 3D surface in Civil 3D directly from a shapefile.