The red squirrel population across England has fallen dramatically over the past century, largely because of squirrelpox, a disease carried by the grey squirrel, which was introduced from North America around 1900. Fewer than 30,000 red squirrels are thought to survive in England today, and most of those are in the north.

Garsdale sits within what conservationists call a core area for red squirrels, sometimes referred to as the Greenfields Stronghold. The combination of suitable woodland habitat, active grey squirrel control, and dedicated local volunteers has helped the reds maintain their presence here. Recent monitoring suggests their range in the Yorkshire Dales may even be expanding.

The reds thrive in the coniferous woodland areas along the valley sides. Grey squirrels tend to favour broadleaf and deciduous woodland along the river corridor, so the two species occupy somewhat different habitats in the dale. Habitat loss from forestry clear felling is an additional threat beyond the greys themselves.

The Garsdale Red Squirrel Group was launched in November 2014 and quickly grew to 38 local members. The work to protect the dale's red squirrels involves a network of local volunteer groups who monitor the population, maintain feeding stations and nest boxes, and carry out grey squirrel control. This grassroots effort accounts for a huge proportion of the conservation work across northern England.

Red Squirrels Northern England coordinates the broader strategy, working with volunteer groups, landowners and the Yorkshire Dales National Park Authority. The Sedbergh Red Squirrels group covers the local area.