In the 1609 Plantation of Ulster, Cuilcagh formed part of lands which were granted to John Sandford of Castle Doe by letters patent dated 7 July 1613 (Pat.

The Cuilcagh area supports a rich assemblage of upland insects, and is one of the most important sites in Ireland for these species.

Species recorded include the water beetles Agabus melanarius, Agabus arcticus, Dytiscus lapponicus, Stictotarsus multilineatus, Hydroporus longicornis and Hydroporus morio and the water bugs Glaenocorisa propinqua and Callicorixa wollastoni.

In 2001 the Cuilcagh Mountain Park was joined with popular tourist attraction the Marble Arch Caves and the Cladagh Glen Nature Reserve to make one of the first UNESCO-recognised European Geoparks.

[12] The Geopark is protected and managed by Fermanagh & Omagh District Council through the staff of the Marble Arch Caves Visitor Centre.

Walkers are advised to allow 2.5–3.5 hours to complete the full 12–14 kilometre round-trip journey.