We were trying to gather a group of 1,000 ewes from a spread in ND with 5,000 sheep total. They're normally in bands of 1,000 spread out over this vast property. After hours on horseback, four wheelers and gators searching unsuccessfully for the group, they finally went up in a plane to locate them. As it turns out, they had gotten in with another group of 1,000, so for reference this is a flock of 2,000 sheep.
In the blanket of sheep pictured, there were three dogs working gathering and directing the sheep to the gate. There's one dog visible on the middle right. I don't know if it's my dog or not. Note the large crevasse-like area in the front of the shot. The terrain was quite rough in places. We were using four wheelers and gators but only the dogs could get to the sheep in many places. So much for four wheelers taking the place of dogs...