Chaparral was the 405-ton 161-foot commercial ferry boat Halcyon and was acquired by the Coast Guard on 19 October 1942 for use on the Great Lakes because of her ice-breaking capabilities. She was converted to a buoy tender by the Toledo Shipbuilding Company of Toledo, Ohio and was commissioned on 4 December 1942.
She was assigned to the 9th Naval District and was based out of Sault Sainte Marie, Michigan, where she was used as an auxiliary icebreaker.
She was decommissioned on 8 February 1946.
Cutter History File. USCG Historian's Office, USCG HQ, Washington, D.C.
Robert Scheina. U.S. Coast Guard Cutters & Craft of World War II. Annapolis, MD: Naval Institute Press, 1982.