The SSSI has a total area of and is the largest area of unenclosed moorland in West Yorkshire. There are extensive areas of blanket bog, interspersed by species-rich flushes and mires. Other habitats include wet and dry heaths and acid grasslands. The blanket bogs are dominated by cotton-grass and heather, with varying amounts of crowberry and bilberry. Areas of wet heath have cross-leaved heath and cranberry. The acid grasslands are dominated by mat-grass and wavy hair-grass with purple moor grass dominating on the wet slopes, along with the heath rush in the wettest places. Chickweed wintergreen and bog pondweed occur here, plants rare in the region. The most species-rich and biodiverse communities are found at wet flushes.