Geneva Basin Iron Fens

Location:    Clear Creek County
Size:   102 acres
Designated:   2004
Landowner:   Clear Creek County

This site contains a very large iron fen which supports the first (and currently only) known population of Sphagnum girgensohnii (a sphagnum moss) in Colorado. The iron fen differs from many others in having large expanses of unvegetated limonite. It also illustrates the effects of groundwater pH on vegetation; spring flow from the south is circumneutral and supports moderately-rich fen vegetation (Salix planifolia, Carex aquatilis); groundwater from the west and north is extremely acidic and supports limonite, sphagnum, bog birch and dwarfed Engelmann spruce. A second fen site was discovered on county property in 2004.