Legolas is untroubled by the snow and can easily run across it.

Gimli looked up and shook his head. ‘Caradhras has not forgiven us,’ he said. ‘He has more snow yet to fling at us, if we go on. The sooner we go back and down the better.’

To this all agreed, but their retreat was now difficult. It might well prove impossible. Only a few paces from the ashes of their fire the snow lay many feet deep, higher than the heads of the hobbits; in places it had been scooped and piled by the wind into great drifts against the cliff.

‘If Gandalf would go before us with a bright flame, he might melt a path for you,’ said Legolas. The storm had troubled him little, and he alone of the Company remained still light of heart.

‘If Elves could fly over mountains, they might fetch the Sun to save us,’ answered Gandalf. ‘But I must have something to work on. I cannot burn snow.’

‘Well,’ said Boromir, ‘when heads are at a loss bodies must serve, as we say in my country. The strongest of us must seek a way. See! Though all is now snow-clad, our path, as we came up, turned about that shoulder of rock down yonder. It was there that the snow first began to burden us. If we could reach that point, maybe it would prove easier beyond. It is no more than a furlong off, I guess.’

‘Then let us force a path thither, you and I!’ said Aragorn.

Aragorn was the tallest of the Company, but Boromir, little less in height, was broader and heavier in build. He led the way, and Aragorn followed him. Slowly they moved off, and were soon toiling heavily. In places the snow was breast-high, and often Boromir seemed to be swimming or burrowing with his great arms rather than walking.

Legolas watched them for a while with a smile upon his lips, and then he turned to the others. ‘The strongest must seek a way, say you? But I say: let a ploughman plough, but choose an otter for swimming, and for running light over grass and leaf, or over snow – an Elf.’

With that he sprang forth nimbly, and then Frodo noticed as if for the first time, though he had long known it, that the Elf had no boots, but wore only light shoes, as he always did, and his feet made little imprint in the snow.

‘Farewell!’ he said to Gandalf. ‘I go to find the Sun!’ Then swift as a runner over firm sand he shot away, and quickly overtaking the toiling men, with a wave of his hand he passed them, and sped into the distance, and vanished round the rocky turn.

The Fellowship of the Ring, Book Two, Chapter 3: The Ring Goes South.