MacRitchies Brook Nature Reserve protects a remnant patch of old forest on the north-facing slopes above Whycocomagh Bay.

The forest includes sugar maple, red maple, eastern hemlock and mature white pine. The underlying karst geology has created sink holes, gypsum outcrops, and small alkaline ponds. These features typically support uncommon plant communities.

This nature reserve is one of a few, small protected areas in the Bras d’Or Lake Plain natural landscape, a productive lowland region.

A power line right-of-way which bisects the reserve is not with the reserve boundary.