Most raster files can be imported by
Input data
r.in.gdal raster.input out=myraster
Import binary arc grid (all files need to be in a directory with .arc suffix)
and create a new LOCATION.
ch20ftdem.arc/
Run the commmand from any LOCATION that you have already set-up
dblbnd.adf hdr.adf log metadata.xml sta.adf w001001.adf w001001x.adf
r.in.gdal ch20ftdem.arc out=ch20ftdem location=ch_sptf