Click on the link below to review excerpts from the Public Documents of the State of Wisconsin 1906. This brief document illustrates the impact of dams in 1906 on the Manitowish, Flambeau, and Chippewa rivers' basin. This brief table does illustrate that the Rest Lake Dam after 15+ years of operation held water levels in 1906 that had Island Lake five feet higher than Rest Lake. Currently, even at draw down for winter, the Manitowish Chain does not drop five feet between Island and Rest lakes.
A more detailed report on the Manitowish River basin was published by the USGS in 1906. This federal document can be found on the Manitowish Waters Historcal Society website as well.