Mapping Mountains – Hill Reclassifications – The Fours – The 400m Hills of England

 

Redmire Forest (SE 041 949) – Sub-Four exclusion

There has been an exclusion from the listing of 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 conducted by Myrddyn Phillips. 

LIDAR summit image of Redmire Forest (SE 041 949)

The criteria for the list that this exclusion 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 is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

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

The name the hill is listed by is Redmire Forest, and it is adjoined to the Great Shunner Fell group of hills, which are situated in the Pennines of northern England, and it is positioned encircled by minor roads, with the B6270 road farther to its north and the A684 road farther to its south, and has the town of Leyburn towards the south-east.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was listed with an estimated c 15m of drop, based on an estimated c 471 summit height, based on interpolation of its uppermost 470m ring contour that appears on the Ordnance Survey 1:25,000 Explorer map, and the 456m col spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

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 col image of Redmire Forest (summit at SE 041 949)

Therefore, the exclusion of this hill from Sub-Four status is due to LIDAR analysis, resulting in a 470.8m summit height and a 456.4m col height, with these values giving this hill 14.4m of drop, which is insufficient for it to be classified as a Sub-Four.

 

The full details for the hill are:

Group:  Great Shunner Fell

Name:  Redmire Forest

OS 1:50,000 map:  98

Summit Height:  470.8m (LIDAR)

Summit Grid Reference:  SE 04191 94946 (LIDAR)

Col Height:  456.4m (LIDAR)

Col Grid Reference:  SE 03697 95217 (LIDAR)

Drop:  14.4m (LIDAR)

 

For the additions, deletions and reclassifications to The Fours – The 400m Hills of England reported on Mapping Mountains since the December 2013 publication of the 1^st edition of this list by Europeaklist please consult the following Change Registers:

 

The Fours

 

Sub-Fours

 

Myrddyn Phillips and Aled Williams (September 2025)