Complex sentence: It was designated as one of the National Parks of England and Wales by statute in 1951 and was, for the first 23 years of its existence, administered by a special committee of Devon County Council.
Split into simpler sentences: It was designated as one of the National Parks of England and Wales by statute in 1951. For the first 23 years of its existence, Dartmoor National Park was administered by a special committee of Devon County Council.