▁a ▁ ▁National ▁Wild life ▁Ref uge ▁in ▁Williams ▁County ▁in ▁the ▁U . S . ▁state ▁of ▁North ▁Dak ota . ▁The ▁refuge ▁consists ▁of ▁Lake ▁Zahl ▁which ▁provides ▁habitat ▁for ▁many ▁species ▁of ▁water f ow l ▁and ▁other ▁species . ▁It ▁is ▁managed ▁by ▁the ▁C ros by ▁W et land ▁Management ▁District . ▁ ▁References ▁ ▁External ▁links ▁ ▁Oh ▁R anger : ▁Lake ▁Zahl ▁N WR ▁ ▁Category : National ▁Wild life ▁Ref ug es ▁in ▁North ▁Dak ota ▁Category : E as ement ▁ref ug es ▁in ▁North ▁Dak ota ▁Category : Pro te cted ▁areas ▁of ▁Williams ▁County , ▁North ▁Dak ota <0x0A> </s> ▁Top ▁ro pe ▁clim bing ▁( or ▁top ▁ro ping ) ▁is ▁a ▁style ▁in ▁clim bing ▁in ▁which ▁the ▁clim ber ▁is ▁secure ly ▁attached ▁to ▁a ▁ro pe ▁which ▁then ▁passes ▁up , ▁through ▁an ▁anchor ▁system ▁at ▁the ▁top ▁of ▁the ▁clim b , ▁and ▁down ▁to ▁a ▁bel ayer ▁at ▁the ▁foot ▁of ▁the ▁clim b . ▁The ▁bel ayer ▁takes ▁in ▁s lack ▁ro pe ▁throughout ▁the ▁clim b , ▁so ▁that ▁if ▁at ▁any ▁point ▁the ▁clim ber ▁were ▁to ▁lose ▁their ▁hold , ▁they ▁would ▁not ▁fall ▁more ▁than ▁a ▁short ▁distance . ▁▁ ▁Top - rop ing ▁is ▁often ▁done ▁on ▁routes ▁that ▁cannot ▁be ▁lead ▁clim bed ▁for ▁one ▁reason ▁or ▁another . ▁Most ▁top - ro pe ▁anch ors ▁can ▁be ▁reached ▁through ▁non - techn ical ▁means , ▁such ▁as ▁by