Import orthofoto to Civil 3D using 'mapiinsert'
Download the orthomosaic from Sitemark Fuse
Open Autocad Civil
Choose the orthomosaic that you just downloaded
*Mapiinsert is limited to files of 500Mb
Open Autodesk Civil 3D, in the upper left corner click to open the drop down list and select “Planning and Analysis”.
On your left click on “Connect” on the home folder, this will open the Data Connections by Provider.
Go to "Add Raster Image or Surface Connection", Give the connection a name, choose the .TIF file from your folder then click the "Connect" button.
Click the "Add to Map" button to load the coordinates from the *.tif file.