Summer 1836
Dr. Heath located and built on the south side of the river, opposite Wisconsin City.
BeloitGrade A · 1 independent source
The evidence
“Clute reached his goal — that is, he came to Rock River, where his further progress was at an end for the time being. During the summer of 1836, Dr. Heath had located and built on the south side of the river, opposite Wisconsin City.”
1879-history-of-rock-county/14-rock-county-ch08-janesville.md, PDF p. 527 / book p. 531
Butterfield, C. W., et al. The History of Rock County, Wisconsin: its early settlement, growth, development, resources, etc. Chicago: Western Historical Company, 1879. Cornell University Library via the Internet Archive, archive.org/details/cu31924028871585.
Grade A: Found on a page of one of our sources