The Black Devon river runs through it towards the town of Clackmannan. A notable feature on the river within Forestmill is a horseshoe weir. This was built in 1711 by George Sorocold to direct water from the river through a sluice into the mill lade that fed the Gartmorn Dam reservoir. The weir was added to the schedule of British listed monuments in 1972.
The Clackmannanshire Council website shows the hamlet with a population of 55 in 2009, making it the smallest settlement in the county. However, in 2009, initial planning permission was granted for a significant expansion of the village by the Muir Group. A proposal to build over 1,200 houses, shops, hotel and golf course has been agreed by the council, despite some opposition by local residents.
- David M. Munro (2006). Scotland: An Encyclopedia of Places & Landscapes. Collins. ISBN 978-0-00-472466-9.
- Samuel Lewis (1 January 1989). Topographical Dictionary of Scotland. Genealogical Publishing Com. pp. 39–. ISBN 978-0-8063-1255-2.
- Roland Paxton; J. Shipway (1 January 2007). Civil Engineering Heritage Scotland: Lowlands and borders. Thomas Telford for the Institution of Civil Engineers. ISBN 978-0-7277-3487-7.
- Scotland; Society for the Benefit of the Sons and Daughters of the Clergy (1845). The New Statistical Account of Scotland: Dunbarton, Stirling, Clackmannan. W. Blackwood and Sons. pp. 2–.
- "Forestmill development boost for Clackmannanshire" STV 18 June 2009