I 'inherited' the family tree work of my aunt and it lists "#15, Hennepin County Death Records" as the source for Francois Jr's death info. I got Francois Sr's birth info from the (still-standing) church in St. Francois du Lac. My wife and I visited there and requested the information. A priest named Gilbert Lemire sent a transcript of the birth recordsof Francois and his 2 siblings. Since then, I've asked for any records for Nicolas, Francois Sr's father. Quite a few descendants of Francois Jr. appear to be buried at St. Vincent de Paul Cemetery in Osseo, MN. Also, it appears Francois Jr. was in Prairie du Chien as late as 1847, when Francois Xavier Chenevert was born (and died after about 3 months).