If your WI ancestors migrated to the San Joaquin Valley 1851-1864 , settling in French Camp, Manteca, or Stockton CA, they are probably buried in the historic pioneer cemetery,East Union Cemetery, Manteca, CA. You can find the burials listed online at http://usgwtombstones.org/california/sanjoaquin.htmlhttp://usgwtombstones.org/california/sanjoaquin.html
Four wagon trains left from Grant Co/Richland WI for the San Joaquin valley town of French Camp,CA and founded and settled Manteca, CA. Two Sperry brothers, Geo. W. and R.O., (soon followed by John Austin Sperry) left in 1851; the Cutler Salmon train with James Reynolds and brothers in 1853; then Joshua Cowell came in 1861; and finally the 100 wagons that made up the train identified as the Reynolds/Harelson/Graves/Howel train arrived in 1864. Some of the pioneers mined gold, but most settled in as grain farmers and tradesmen.
The Manteca CA East Union Cemetery,is found on the corner of Union Rd (formerly Reynolds Rd) and Louise, the cornerfarmed by JamesReynolds and his sons.