pair of islands a road had to be "tramped."

Thorpe and the rest were put at this disagreeable job. All day long
they had to walk mechanically back and forth on diagonals between
the marks set by Radway with his snowshoes. Early in the morning
their feet were wet by icy water, for even the light weight of a
man sometimes broke the frozen skin of the marsh. By night a road
of trampled snow, of greater or less length, was marked out across
the expanse. Thus the blanket was thrown back from the warm earth,
and thus the cold was given a chance at the water beneath. In a
day or so the road would bear a horse. A bridge of ice had been
artificially constructed, on either side of which lay unsounded
depths. This road was indicated by a row of firs stuck in the snow
on either side.

It was very cold. All day long the restless wind swept across the
shivering surface of the plains, and tore around the corners of the
islands. The big woods are as good as an overcoat. The overcoat
had been taken away.

When the lunch-sleigh arrived, the men huddled shivering in the lee
of one of the knolls, and tried to eat with benumbed fingers before
a fire that was but a mockery. Often it was nearly dark before their
work had warmed them again. All of the skidways had to be placed on
the edges of the islands themselves, and the logs had to be travoyed
over the steep little knolls. A single misstep out on to the plain
meant a mired horse. Three times heavy snows obliterated the roads,
so that they had to be ploughed out before the men could go to work
again. It was a struggle.