Moor Brook, Okehampton, Dartmoor National Park. Moor Brook rises near West Mill Tor on Dartmoor's north plateau. It flows down to Okehampton Camp on its way to Lower Halstock. The brook tumbles through Halstock Wood and meets the East Okement River at West Cleave in the East Okement Valley. This last stretch of Moor Brook is stunning. Photo by Dartmoor Giant.