Corthoon covers a 140.19 ha (346.4 acres) area and is the 310th largest townland (out of a total of 1508) in County Leitrim.
[2] Corthoon falls within the Electoral Division of Ballaghameehan, the Civil Parish of Rossinver, in the Barony of Rosclogher.
Cattle milk production was common until the 1970s but this was gradually phased out following Ireland’s entry into the EEC.
Milk produced in the townland was transported to the local creamery, the Killasnett Co-op, in Manorhamiltion.
Corthoon is 5 km (3.1 mi) south of St Aidans Catholic Church, Ballaghameehan[9] in Rossinver Parish via the R282 and L6180.