Complex sentence: Over 18,000 grazing permits and leases are known to exist on BLM managed public lands, however season of use and forage use stipulations are stipulated on the permits and leases and grazing control can be targeted.
Split into simpler sentences: Over 18,000 grazing permits and leases are known to exist on BLM managed public lands. Season of use and forage use stipulations are stipulated on the permits and leases; grazing control can be targeted.