Lake Minnetonka Underwater Archaeology Project: Anomaly Identification and Assessment

During the LMUAAIA Project, that encompassed the field seasons of 2020 (funded by privately donated funds) and 2021 (funded by a small amount of privately donated funds and grant 2104-25856), MHM investigated 3 known wrecks and 37 unknown anomalies. Of these targets, the 3 wrecks and 36 anomalies were documented using SCUBA and 1 target was investigated using an ROV (Remotely Operated Vehicle). The fieldwork was conducted during August-September 2020 and May-September 2021. The LMUAAIA Project produced interesting and significant results, particularly identifying 11 new wrecks, 4 new submerged maritime sites (2 of which are associated with other known archaeological sites), 3 other objects, and 19 natural objects or false sonar returns. The number of unknown anomalies identified during the LMUAAIA Project is 37. These wrecks and sites join dozens of other submerged cultural resources already identified in the lake. After the completion of the LMUAAIA Project fieldwork in September 2021, there are now 94 identified wrecks on the bottom of Lake Minnetonka or that were once on the bottom, including a Woodland Culture dugout canoe removed from the lake in 1934. Of these wrecks, 62 of them have 61 Minnesota archaeological site numbers; 2 wrecks are features of one site. Further, 4 other types of maritime sites have archaeological site numbers and there are 39 maritime sites or objects without numbers. Additionally, 53 'other' objects have been identified that do not have site numbers, among them 13 vehicles that include 4 snowmobiles, 2 trucks, and 7 cars. During the LMUAAIA Project specifically of the 37 unknown anomalies and 3 known wrecks investigated MHM and its volunteers accumulated important data about the wrecks and confirmed the existence of 11 new wrecks, 4 new submerged maritime sites (2 of which are associated with other known archaeological sites), 3 other objects, and 19 natural objects or false sonar returns. Comparing and associating these new sites with known sites increases our understanding of the historical context within which these cultural resources operated or were exploited by Minnesota's. For this project, Anomalies 698 and 1039 are particularly on target for this type of association since they are parts of 2 known underwater and maritime sites: the Minneapolis Wreck (21-HE-403) and the Big Island Steamboat Pier, Amusement Park, and Veteran's Camp Archaeological Site (21-HE-402). Firstly, the Dakota Unfinished Dugout Canoe Wreck (21-HE-557) is the only known Native American dugout canoe in situ in Minnesota; and likely the only unfinished dugout in situ in the US. The incomplete nature of the dugout is archaeologically significant because of the amount of useful information that has been accumulated pertaining the construction process: score lines, cuts, axe cuts, and de-barking marks. It is possible the Dakota Unfinished Dugout Canoe Wreck was constructed as early as 1683, but using the the C14 data and relative dating of the site in combination more strongly supports a date range of 1802-1850; she is the oldest wreck on the lake bottom. However, the Lake Minnetonka North Arm Dugout Canoe was constructed around 1,000 years ago, but she is no longer on the lake bottom; she is houses at the West Hennepin History Center in Long Lake. MHM contends the Steel Wineglass Stern Wreck (21-HE-561) was constructed around 1900 and had a long working life, likely sinking around 1930. She is only the second steel wineglass stern wreck identified in Minnesota; the other site is 21-WA-122 in Forest Lake in Washington County, identified by MHM in 2020. This sophisticated small boat design takes a skilled boatwright to construct; to fabricate an example out of steel requires even more skill. Further, the Steel Wineglass Stern Wreck is the oldest steel wreck on the bottom of lake, followed by the Steel Motor Boat Wreck (21-HE-510) and the Steel Row Boat Wreck (21-HE-530). With the inclusion of 21-HE-561 to the growing number of small steel wrecks on the bottom of Lake Minnetonka, these nautical archaeological sites join others with similar natures in Lake Pulaski, Christmas Lake, Medicine Lake, White Bear Lake, Prior Lake, and Lake Johanna. Additionally, with the possibility that 21-HE-561 may have been constructed by a Minnesota boat-building company, she is an important link in the State?s metal craft production history. While her manufacturer is currently unknown, 3 metal wrecks also analyzed during the LMNA-10 Project - the Larson Watercraft Seaman Wreck (21-HE-555), the Crestliner Sportsman Wreck 2 (Anomaly 1024), and the Larson Game Warden Wreck (Anomaly 726) - were definitely constructed by Minnesota-based companies. Other Minnesota metal watercraft construction companies represented as wrecks in Lake Minnetonka include Alumacraft and Lund. Further, the Homebuilt Wood and Steel Composite Wreck (21-HE-562) represents the first of this type yet identified by MHM in any Minnesota lake - basically a wooden boat sheathed in steel. The steel was not applied to the wreck during her life on the water, however; she was constructed that way. All 15 small open boat-style metal wrecks - identified to date - on the lake bottom (not including 3 aluminum canoes) were not only produced by various manufacturers or represent home-builds, they are of different models from each other or carry different attributes from each other, supplying great variety in Minnesota's nautical and underwater archaeological records. Also from the early 20th Century, the Fast Motor Boat Wreck (21-HE-560) is the largest wooden wreck investigated during the LMNA-10 Project. Additionally, she is the largest wooden personal watercraft so far identified on the bottom of Lake Minnetonka. Several larger wooden wrecks are present on the bottom of the lake, of course, but all of these vessels were used commercially as forms of public transportation, excursion vessels, and working boats such as barges and pile drivers. The Fast Motor Boat Wreck represents a significant 'culture' on Lake Minnetonka during the first 40 years of the 20th Century - that of fast motor boat racing. Important local and national watercraft designers and builders such as Dingle Boat Works, Moore Boat Works, Ramaley Boat Works, Gar Wood, Hackercraft, Chris Craft, and others constructed hundreds of boats with large inboard engines, built for speed. The proliferation of boat racing magazines beginning in the early 1900s attests to the nation-wide interest in producing fast racers that often traveled to regional races, often carrying engines constructed by local firms Westman and Globe. While sailboat regattas were and continue to be regular occurrences, speedboat racing is a thing of the past, ending before World War II. However, speed boat rides were offered at the Excelsior Amusement Park in the 1930s and 1940s; after World War II, the ownership of personal watercraft exploded and regular small boat rides at the Park became redundant. It is hoped that MHM can determine the identity of 21-HE-560 in the future; 1 candidate currently exists - the Miss Minnetonka. On October 6, 1923, O.H. Gray's 'speed launch' Miss Minnetonka sank to the bottom of Lake Minnetonka after an explosion of unexplained origin. One woman and 4 men (including Australian actor Snowy Baker) swam toward shore for 40 minutes before being picked up by a rowboat. Miss Minnetonka was launched for the first time in Spring 1923. Interestingly, another fast boat owned by O.H. Gray, the Bluebird, caught fire and sank in shallow water at a dock on Brackett's Point on August 25, 1923 - 6 weeks before Miss Minnetonka exploded and sank. In consideration of the details of Bluebird's story, she is not 21-HE-560, and MHM assumes she was raised for parts due to the shallow nature of the water where the wreck burned - 6 feet deep. Unfortunately, at this time, not enough evidence exists to prove the identity of The Fast Motor Boat Wreck. Smaller wooden wrecks - under 25 feet - investigated during the LMNA-10 Project represent models for different purposes. The Wooden Transomless Wreck (21-HE-556) is a fishing boat, the Wooden Inboard Motor Boat Wreck (21-HE-564) is a pleasure craft speed boat, the Wooden C-Scow Wreck (21-HE-559) is a racing sailboat, and the Owens Cruiser Deluxe Wreck (21-HE-565) is a small floating house that could feed and sleep several people. All wooden boats, they span the years 1910-1959 in construction and until 1970 on the water. The Wooden Transomless Wreck joins dozens of small wooden wrecks MHM has identified in Lake Minnetonka and nearly every other lake where sonar surveys and underwater archaeology projects have been conducted. The Wooden Inboard Motor Boat Wreck, while representing the pleasure boating and 'boat show' cultures, it also falls into the 'lake accidents' or 'incidents' categories because of the virtual 'falling apart' of the boat beneath the feet of the 2 men on board. And, like the story of the Owens Cruiser Deluxe Wreck, the sinking of 21-HE-564 resulted in a fatality. The Owens accident's 3 deaths is one of the largest casualty numbers in 'modern' history, and the location of the runabout involved in that collision is still unknown. The Wooden C Scow Wreck is the second wooden sailboat identified on the bottom of the lake, the first being the Wooden Sloop Wreck (21-HE-486) that was constructed in the 1890s-early 1900s. The Sloop probably functioned only as a pleasure craft, while the C Scow was constructed to be a racer; although the fiberglassed nature of the Scow suggests she may not have been racing during her latter years. Another wreck that began her life as a wooden boat, the Homemade Fiberglassed Utility Wreck (Anomaly 1010) appears to have had a long life on the water as an open outboard fishing boat. Then, at some point, she was fiberglassed using large sheets; an obvious home job on an homemade boat. Anomaly 1010 is the 'newest' wreck MHM has identified on the bottom of Lake Minnetonka since she sank between mid-May 2019 and ice-in during the Autumn of 2020. Further, A1010 is the first wreck investigated by MHM where the acoustical sonar signature indicated the watercraft had 'slid' or was dragged somehow across the lake bottom before coming to rest in its current condition; dive reconnaissance confirmed the sonar evidence. Hopefully MHM can determine if she is a kit boat, and possibly a locally-produced kit such as Taft or Luger, in the future. Two more somewhat 'modern' wrecks identified during the LMUAAIA Project are manufactured from fiberglass: the Fiberglass Sailboat Wreck 2 (Anomaly 856) and the Upright Larson All-American 165 Wreck (Anomaly 884). The second fiberglass sailboat recognized on the lake bottom, poor visibility prevented MHM from identifying the vessel's brand or many details about her beyond her red and white color, and the size and look of the rudder. Contrastingly, MHM can identify most of the attributes of Anomaly 884 because of the previous study of a museum-held example in 2020. The Larson All-American 165 was the best-selling boat in the world during the vessel's heyday in the late 1950s into the 1970s. It is unsurprising that at least 1 of this model of boat has made it to the bottom of Lake Minnetonka. What makes Anomaly 884 archaeologically interesting, however, is the upright nature of the wreck, standing in the water column. She is weighed down/held in place by the large Evinrude Starflite III outboard motor, and possibly assisted by the boat's flotation foam. Anomaly 884 joins 4 other wrecks in the lake that stand up in the water column: the Fiberglass Drag Boat Wreck (Anomaly 23), the Red Fiberglass Wreck (Anomaly 32), the Alumacraft Model A Wreck (Anomaly 462), and the Chris Craft Stinger 260 Wreck (Anomaly 749). One car also stands somewhat into the water column as well. Prior Lake also has a wreck upright in the water column and Medicine Lake has 2 cars imbedded into the lake bottom at 90 degree angles. As more Minnesota wrecks are documented, the changes in watercraft design and construction will more completely fill-out the maritime historical record. Many of the smaller craft on the bottom of Lake Minnetonka - including the Dakota Unfinished Dugout Canoe Wreck represent over 220 years of our relationship with historical personal watercraft. When the internal combustion engine began to replace steam-powered boats in the late 19th and early 20th Centuries, watercraft operation by a single person became possible since a boiler operator was no longer necessary. The rapid development of the outboard motor set up the proliferation of personal watercraft, made of wood, steel, aluminum, and fiberglass. The higher speeds attained by internal combustion engines also led to changes in hull design. Other maritime anomalies identified during the LMUAAIA Project, the Minneapolis Anchor (Anomaly 698) and the Big Island Rubble Pile (Anomaly 1039), enlarge other already-established archaeological sites; MHM contends that more rubble piles will be identified and additional anchors may be discerned in the future. Two other anomalies, the Pontoon (A908) and the Arched Rubber Pipe (A1053) are maritime objects. The Pontoon was part of a pontoon boat or raft, while the Pipe was part of the maritime infrastructure of the lake's shoreline. The Rusty Barrel (Anomaly 731), the Metal Frame (Anomaly 862), and the Aluminum Ladder (Anomaly 898) are among dozens of objects blown into the lake by strong storms or deposited there by the habit of disposing of unwanted objects on the ice or dumped from boats. The diversity of nautical, maritime, and underwater sites so far identified in Lake Minnetonka are tangible examples of the rich maritime history of the area. Through research, diving on wrecks and anomalies to collect pertinent data, and ensuring that the collected information is accessible by the public, MHM will continue to investigate Lake Minnetonka's submerged cultural resources into the future. As shown by the 7 new wrecks identified by MHM during this project, the continued re-scanning of several sections of Lake Minnetonka is warranted. Comparison of sonar data recorded from different directions and various times during the Spring, Summer, and Autumn have revealed new sites, as well as facilitating the recognition of false targets that do not require reconnaissance using SCUBA. This new data allows MHM to produce smart and efficient dive plans; this will continue into the future. The results of the LMUAAIA Project summarized above is connected to all the work that came before and that will come after its completion. It is clear that the types of sites that exist in Lake Minnetonka are diverse, archaeologically and historically significant, and worthy of great attention. To date, the watercraft located on the bottom of Lake Minnetonka represent nearly 1,000 years of Minnesota's maritime history and nautical archaeology. In the historic period, the known wrecks represented in the lake span over 220 years of local maritime culture. The data collected during Lake Minnetonka Projects have been utilized to create the ever-changing Lake Minnetonka Multiple Property Documentation Form, a guide that will be used to nominate Lake Minnetonka's submerged cultural resources to the National Register of Historic Places (NRHP). At this point, the Wayzata Bay Wreck (21-HE-401) has been successfully nominated to the NRHP by MHM. Lastly, the large and significant data produced during the Lake Minnetonka projects has and will be used for comparison purposes as MHM identifies wrecks and maritime resources on the bottom of other Minnesota lakes. To date, these bodes of water include White Bear Lake, Lake Waconia, Prior Lake, Lake Johanna, Medicine Lake, Lake Pulaski, Forest Lake, and Christmas Lake.