sam dro gs ▁very ▁met icul ously ▁based ▁on ▁years ▁of ▁experience . ▁The ▁days ▁are ▁carefully ▁divided ▁for ▁each ▁t sam d rog ▁to ▁sust ain ▁the ▁whole ▁winter ▁while ▁also ▁mit ig ating ▁gra zing ▁pressure . ▁ ▁Summer ▁gra zing ▁grounds ▁ ▁Summer ▁gra zing ▁grounds ▁are ▁located ▁at ▁temper ate ▁and ▁al pine ▁regions ▁where ▁cattle ▁migr ate ▁when ▁climate ▁in ▁tropical ▁and ▁sub - t rop ical ▁regions ▁become ▁hot ▁and ▁hum id . ▁However , ▁the ▁park ▁has ▁less ▁summer ▁gra zing ▁ground . ▁ ▁In ▁the ▁Black ▁Mountain ▁regions , ▁y aks ▁from ▁Ph obj ik ha ▁Valley ▁gra ze ▁in ▁the ▁al pine ▁me adows ▁during ▁summer . ▁The ▁y aks ▁migr ate ▁to ▁the ▁lower ▁alt itude ▁areas ▁of ▁the ▁Ph obj ik ha ▁Valley ▁during ▁winter s ▁when ▁Black ▁Mountain ▁remains ▁shr oud ed ▁in ▁snow . ▁ ▁There ▁are ▁six ▁y ak ▁her ders ▁from ▁Ph obj ik ha ▁Valley ▁who ▁migr ate ▁to ▁the ▁past ures ▁in ▁Black ▁Mountain , ▁each ▁ow ning ▁an ▁average ▁of ▁ 5 6 ▁y aks . ▁It ▁is ▁likely ▁that ▁over ▁ 3 0 0 ▁y aks ▁will ▁gra ze ▁in ▁the ▁limited ▁past ures ▁in ▁rotation ▁for ▁around ▁ 5 ▁months ▁from ▁May ▁to ▁September . ▁ ▁When ▁cattle ▁migr ate ▁to ▁summer ▁gra zing ▁grounds ▁at ▁temper ate ▁and ▁sub - al pine ▁regions , ▁the ▁y aks ▁move ▁up ▁to ▁higher ▁alt itudes ▁in ▁al pine ▁areas . ▁When ▁the ▁cattle ▁migr