Although the Survey did not include every inhabitant of Bishopdale Chase, it did include all who held sufficient property to be liable to taxation, so a broad comparison can be made between the mills and the communities they served. While there will have been exceptions, Thoralby Mill will have ground grain for most of the 65 taxpayers in Thoralby, the 34 in Bishopdale and the 27 in Newbiggin. West Burton Mill served the 27 taxpayers in West Burton and the 21 in Walden, while Aysgarth Mill only served the inhabitants of Aysgarth, where there were 12 taxpayers. The local importance of Thoralby Mill is demonstrated not only by its value and the rent it paid, but also by the fact that it was serving a much larger community of taxpayers – 126 compared with 48 in West Burton Mill’s catchment area and only 12 in Aysgarth’s. It is likely that this did not reflect the true size of Aysgarth, part of which probably belonged to other landowners who may have had their own mill.

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Not only was Thoralby Mill more significant than its neighbours, but its miller also had a higher standing in the community. In addition to being the miller at Thoralby, George Dodsworth had two other houses, 63 acres of meadowland and 89 pasture gates on the open grazing land surrounding the village. By comparison, Henry Hodgson at West Burton Mill and Robert Dixon at Aysgarth Mill were not recorded as having any property other than their mills. Only one mill in the Lordship of Middleham in 1605 was more prosperous than the one at Thoralby: Bainbridge Mill was recorded as worth £16 per year and paying £7. 13s. 4d (£7.67) a year in rent.

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In 1628 the Crown sold the Lordship of Middleham to the aldermen and council of the City of London. This included a water corn mill at Thoralby with an annual rent of £5 13s. 4d. and a fulling mill with an annual rent of 30 shillings. The City of London sold the Lordship of Middleham in parcels to various purchasers between 1652 and 1663. Thoralby Mill was purchased on 26 December 1656 by "George Dodsworth the younger of Langrig, Peter Metcalfe of Medstones and Edward Fawcett of Kedstones, yeomen". The mill, or at least part of it, remained in the hands of the Dodsworth family for most of the 17th century. In a will dated 12 February 1681, "George Dodsworth ye elder of Newhouses in Bishopdale" stated "I give & bequeath unto Elizabeth Dodsworth my wife ye Moiety or one halfe of ye Water Corne Mill & Kilne lyeing at Thorolby to have & receive ye yearly profits & benefit Issueing & arising out of ye same during ye tearme of her Naturall life and after her decease to fall & descend to my sonn George Dodsworth his heires for ever." There appear to have been at least three George Dodsworths who held Thoralby Mill during the 17th century: the one mentioned in the 1605 survey as living in Thoralby, George Dodsworth the younger who lived at Langrig (Longrigg) in 1656 and may have been the same person who was referred to as George Dodsworth the elder of Newhouses in 1680, and died in 1681, and his son, the George Dodsworth who stood to inherit after the death of his mother Elizabeth. The 1680 document is also the first to record a kiln at Thoralby Mill for drying the corn before it was ground.

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Sometime before or during the early 18th century, the mill moved from alongside Bishopdale Beck, where it would have been at risk of flooding, to a safer position higher up the hillside. This move took the mill onto its present site. A weir was built a third of a mile upstream at Dam Stakes to dam up the water and divert it into a long leat or mill race that was constructed to bring the water to the top side of the mill. This was done so that the new mill could have a more powerful overshot or backshot waterwheel (see diagrams below) whereby the weight of the water falling into buckets from above the waterwheel powered the mill machinery.