The Illgraben is a 10 km² steep side valley located in Switzerland. This active debris flow catchment supplies 5-15% of the total sediment load of the Rhône River upstream of Lake Geneva. The 30-80° steep catchment slopes host frequent rock falls and slides. From 2012 to 2014, a network of up to ten Nanometrics Trillium Compact 120s broadband seismometers, sampled by Digos DataCube³ext loggers at 200 Hz (and later by centaur), was deployed in and around the catchment to monitor distributed geomorphic activity. Waveform data is available from the GEOFON data centre, under network code 9J, and is fully open.