▁" M itt raph ap ▁Road ", ▁the ▁main ▁road ▁crossing ▁the ▁range ▁between ▁Sar ab uri ▁and ▁N akh on ▁R atch as ima , ▁was ▁built ▁in ▁ 1 9 5 0 . ▁ ▁Prote cted ▁areas ▁These ▁mountains , ▁together ▁with ▁the ▁Sank am pha eng ▁Range ▁at ▁their ▁southern ▁limit , ▁form ▁the ▁D ong ▁Ph ay ay en - K ha o ▁Y ai ▁Forest ▁Complex , ▁which ▁includes ▁several ▁national ▁par ks . ▁This ▁area ▁was ▁ins cribed ▁on ▁the ▁UN ES CO ▁World ▁Heritage ▁List ▁in ▁ 2 0 0 5 . ▁Alt ogether ▁ 6 , 1 5 5   km 2 ▁are ▁protected ▁in ▁the ▁complex . ▁In ▁mid - 2 0 1 6 ▁UN ES CO ▁briefly ▁considered ▁placing ▁the ▁D ong ▁Ph ay ay en - K ha o ▁Y ai ▁Forest ▁on ▁a ▁list ▁of ▁end anger ed ▁World ▁Heritage ▁sites ▁because ▁Th ailand ▁had ▁not ▁done ▁enough ▁to ▁stop ▁illegal ▁logging ▁of ▁ph ay ung ▁( S iam ese ▁rose wood ) ▁trees . ▁ ▁Other ▁protected ▁areas ▁in ▁the ▁D ong ▁Ph aya ▁Y en ▁mountains ▁are : ▁ ▁Pa ▁Hin ▁Ng am ▁National ▁Park ▁ ▁S ai ▁Th ong ▁National ▁Park ▁Ph u ▁Kh iao ▁Wild life ▁San ctu ary ▁Tat ▁Ton ▁National ▁Park ▁Nam ▁Ph ong ▁National ▁Park ▁Ph u ▁Lan ▁Ka ▁National ▁Park , ▁ ▁S ap ▁Lang ka ▁Wild life ▁San ctu ary ▁K ha o ▁Som ph ot ▁Non - h un ting ▁Area