At approximately 3:30 pm, an estimated 300 protestors trespassed onto property just west of Hwy 1806 where DAPL workers were doing construction. The protestors entered the property after cutting/damaging the fence and went a significant distance onto the property to engage the construction equipment. Protestors also brought 20-30 horses and possibly vehicles onto the property. Private security met the protestors and security had K-9’s. There was conflict between security and the protestors which led to several security workers sustaining injury. Pepper mace was used against the protestors. Law enforcement arrived and were able to get the protestors to leave the property. No arrests were made at the scene but investigation continues.