Coal bursts (damaging seismic events in underground coal mines) pose a substantial threat to operations and mine workers. The underground coal mines in Colorado’s North Fork Valley (NFV) have experienced many coal bursts, often with distinct characteristics from those of other US coal mining regions. To better understand these events and manage their associated risks, the National Institute for Occupational Safety and Health undertook a long-term monitoring campaign at the Elk Creek Mine in the NFV. The monitoring efforts included a seismic network composed of both surface and underground sensors, borehole pressure cells (BPCs), instrumented support Cans, convergence monitors, ground condition surveys, and several other data sources. This dataset consists of the event waveform files from the seismic network for the 983,379 events that were detected during the monitoring campaign. The waveforms are stored in HDF5 files that are broken up by week. Within the HDF5 files, the data are organized by station id, event time, and channel. The amplitudes are velocity in meters/second.   This is download 27 of 48 and corresponds to the time range between December 26, 2011, and January 2, 2012.