June 1836
Robert and Daniel Stone started from Michigan for the Wisconsin Rock River valley (Fulton).
The regionGrade A · 1 independent source
The evidence
“In the month of June, 1836, Robert and Daniel Stone started from the State of Michigan and came to the Territory of Wisconsin. Continuing their course westward until they reached the valley of the Rock River, they saw at a glance that the stream, with its abundant waterpower, and the clean, smooth prairies, with their rich soil, possessed advantages which needed only the stalwart arms and resolute hearts of hardy men to develop into excellent homes.”
1879-history-of-rock-county/13-rock-county-ch07-town-histories.md, PDF p. 503 / book p. 507
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