Do mountains run through the majority of North Korea?

Check this physical map.

http://www.google.com/imgres?imgurl=http://media.maps.com/magellan/Images/northkorearah.gif&imgrefurl=http://www.maps.com/map.aspx%3Fpid%3D12244&h=413&w=550&sz=55&tbnid=YHntm6dZvomVMM:&tbnh=100&tbnw=133&prev=/images%3Fq%3Dnorth%2Bkorea%2Bphysical%2Bmap&zoom=1&q=north+korea+physical+map&hl=en&usg=__D-pK7eZHze-uhmYSVIHDyg_hhsE=&sa=X&ei=E4cGTefdLYKnnQfps8nlDQ&sqi=2&ved=0CB4Q9QEwAg