I doubt it was the “protesters” who blocked the interstate.
The protester started to block the on-ramp to the interstate, then began to actually slow down and block it. The NSP came along and got things moving, then CLOSED I15 so that the BLM could move out.
The protesters were even nice enough to move to the other side of the overpass so they wouldn’t spook the cattle when they (the cattle) were released.