Mapping Mountains – Summit Relocations – The Fours – The 400m Hills of England

North Molton Ridge (SS 778 325) 

There has been a Summit Relocation that is retrospective to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis initially conducted by Aled Williams and subsequently by Myrddyn Phillips. 

LIDAR image of North Molton Ridge (SS 778 325)

The criteria for the list that this summit relocation applies to are:

The Fours – The 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills; the 400m Sub-Fours, the 390m Sub-Fours and the 390m Double Sub-Fours.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is North Molton Ridge, and it is adjoined to the Dunkery Beacon group of hills, which are situated in the counties of Somerset and Devon, and it is positioned encircled by minor roads, with the A399 road farther to its west, the A361 road and the B3227 road farther to its south, and has the town of South Molton towards the south-west.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with an estimated c 56m of drop, based on the 435m summit spot height adjoined to a triangulation pillar that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map that is atop an ancient tumulus and which is positioned at SS 77968 32459, and an estimated c 379m col height, based on interpolation of 10m contouring between 370m – 380m. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of North Molton Ridge (SS 778 325)

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, the details for this hill had been analysed via LIDAR and its summit relocated to a different tumulus.  Latest LIDAR analysis gives the highest ground on this hill as 435.1m positioned at SS 77838 32544 and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 435.1m and this is positioned at SS 77838 32544.  This position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is positioned to a different feature and is approximately 130 metres north-westward from where the originally listed summit is positioned.

 

The full details for the hill are:

Group:  Dunkery Beacon

Name:  North Molton Ridge

OS 1:50,000 map:  180

Summit Height:  435.1m (LIDAR)

Summit Grid Reference (New Position):  SS 77838 32544 (LIDAR)

Col Height:  381.8m (LIDAR)

Col Grid Reference:  SS 77925 33972 (LIDAR)

Drop:  53.3m (LIDAR)

 

Myrddyn Phillips and Aled Williams (February 2024)