The fell was once well wooded, and retains a good covering of trees on the lower slopes, as well as scattered larches and pines higher up.

Its rock is unusual for the Lake District, a reddish conglomerate of Devonian age, which has been eroded to form a rounded hill with smooth outlines and no rocky crags.

The first element of the name derives from the Common Brittonic word found in modern Welsh as moel ("bare"), and this must once have constituted the whole name of the hill.

Rock is represented only by a number of large erratic boulders, mainly on the north slopes, but also by the Cloven Stone near a barn to the south of the fell.

[2] The hill is triangular in plan (indeed, it is almost the shape of a broad arrow-head) with the apex pointing west, down the steep "nose" of the fell, and with the gentler, broader eastern slopes divided by two shallow valleys which drain into the Wham Sike and Routing Gill Beck.

This watershed is formed by a low ridge, barely perceptible in places, which connects the Northern and Eastern Fells.

[3] Great Mell Fell is a quiet place of refuge within the surrounding agricultural land, for wildlife as well as for walkers.

The sheltered lower eastern slopes are well covered by mixed woods of oak, rowan, birch, holly and Scots pine.

Alfred Wainwright includes a drawing of one of the signs in his 1955 guide book, but he himself apparently ignored the warnings and explored the fell anyway.

While there are no crags on Great Mell Fell, boulders of the conglomerate may be seen in places, especially on the north slope, and it may also be seen in the two stream beds.