Last week, the Ordnance Survey made a mountain out of an old hill – Calf Top in the Yorkshire Dales. The beige loaf of a mount, dusted occasionally with snow, surpassed the mountain threshold by just six millimetres. A quarter of an inch. One third of a five pence coin.
‘A hill needs to be 609.6 metres, or 2,000 feet, above sea level to be classified as a mountain,’ says Welsh hill walker and mountain expert, Myrddyn Phillips. Phillips spent two hours collecting height data on the peak in question in 2010 and again in 2016. Calf Top did not register as tall enough the first time, measuring a tantalisingly close 609.579 metres. ‘The result was so close to the threshold that the OS advised us to go back and gather a further four hours of data,’ he says explaining that the longer an amount of time is spent on a mountain candidate, the more accurate the data becomes. ‘However, we are only talking tiny margins of improved accuracy,’ he clarifies.
Luckily, a small margin was all Calf Top needed. When Phillips came down the summit for a second time, it clocked in at 609.606m. ‘That was thrilling’ he says, ‘as we never know what the results are going to be until they are post-processed. For the known height to be changed six years after the first assessment felt like a job well done.’
Why is 609.6 metres the magic number between mountainous glory and hilly ignominy? For such a precise measurement, the answer is actually somewhat arbitrary as there is no universal distinction between the two. In the US, mountains are generally defined as rises over 1,000 feet, though there are many ‘mounts’ that are smaller. ‘Meanwhile, the UK’s 2,000 feet has mainly historical merit,’ says Phillips. ‘There has been a long tradition of list authors cataloguing the 2,000ft mountains of England and Wales and referring to these as such. Calf Top has become the 317th.’
In Scotland, where the Highland fault line has created thousands of peaks at much higher elevations, there is less need for a distinction between the two. ‘In Scotland, the word “hill” can be used in a generic way to encompass everything that is of significant height,’ says Phillips. ‘Even Everest is just a big hill.’