EXHIBIT 21.1 Subsidiaries of the Registrant. EXHIBIT 21.1 Subsidiaries of the Registrant State of Doing Business Name of Subsidiary Incorporation As - ----------------------------------------------------------------------------- ICG 161, L.P. Delaware -- ICG Corporate Headquarters, L.L.C. Colorado -- ICG Equipment, Inc. Colorado -- ICG Mountain View, Inc. Colorado -- ICG NetAhead, Inc. Delaware --