There is a Charles Schenck buried in the Walnut Hill Cemetery in Baraboo, 1867-1948. I will see if I can locate more on this person.
In the Madison Capitol times on Nov, 18, 1931. Under 50 years ago is the following:
Mrs. Fritz Nether, Dodgeville, daughter of Reverend Charles Schenck, Middleton dies. This would have taken place in 1881.
There is a St. Lukes Lutheran Church in Middleton which has been there for a long time. I will see if the history of this church includes this pastor. It is not too far from Roxbury.
I live about tin miles from Roxbury.
Fish Lake is on Section's two and three in the Town of Roxbury. You may also try to reach the town clerk for records.