Could be 5 mar 1857.

http://search.ancestry.com/cgi-bin/sse.dll?indiv=try&db=MNstatecen&h=2454333

https://familysearch.org/pal:/MM9.1.1/M93Z-MR7

Homestead of land. 149N 039W S 4 S 1/2 NW 1/4 Lot/Trct 3 Lot/Trct 4 NW corner 47.586038, -95.639167 SW corner 47.579139, -95.628316

http://search.ancestry.com/cgi-bin/sse.dll?rank=1&new=1&MSAV=1&gss=angs-c&gsfn=Andrew&gsfn_x=XO&gsln=Anderson&gsln_x=NP_NN&msbdy=1856&msbpn__ftp=Norway&msrpn__ftp=Minnesota%2c+USA&msrpn=26&msrpn_PInfo=5-%7c0%7c1652393%7c0%7c2%7c3247%7c26%7c0%7c0%7c0%7c0%7c&cpxt=0&uidh=fd7&_83004003-n_xcl=f&cp=0&msrpn__ftp_x=1&msrpn_x=XO&msbdy_x=1&msbdp=1&pcat=CEN_1900&h=3304157&recoff=8+10&db=MNstatecen&indiv=1&ml_rpos=51

http://search.ancestry.com/cgi-bin/sse.dll?indiv=1&db=1910USCenIndex&rank=1&new=1&MSAV=1&gss=angs-d&gsfn=Roy&gsln=Bly&gsln_x=NP_NN&msbdy=1907&msbpn__ftp=Minnesota&dbOnly=_83004006%7c_83004006_x%2c_83004005%7c_83004005_x&uidh=fd7&pcat=35&fh=0&h=160058804&recoff=&ml_rpos=1

Andrew went to Canada and came back with a daugther, Esther. They are recorded crossing the border in Jun 1915 at Eastport, Idaho.

http://search.ancestry.com/cgi-bin/sse.dll?db=CanadianBC&h=710842&ti=0&indiv=try&gss=pt

http://search.ancestry.com/cgi-bin/sse.dll?rank=1&new=1&MSAV=1&gss=angs-g&gsfn=Andrew&gsfn_x=NP_NN_NIC&gsln=Bly&gsln_x=NP_NN&msbdy=1856&msypn__ftp=Montana%2c+USA&msypn=29&msypn_PInfo=5-%7c0%7c1652393%7c0%7c2%7c3248%7c29%7c0%7c0%7c0%7c0%7c&cpxt=0&catBucket=rstp&uidh=fd7&_83004003-n_xcl=f&cp=0&pcat=ROOT_CATEGORY&h=107447404&db=1920usfedcen&indiv=1&ml_rpos=3

http://search.ancestry.com/cgi-bin/sse.dll?rank=1&new=1&MSAV=1&gss=angs-g&gsfn=Andrew&gsfn_x=NP_NN_NIC&gsln=Bly&gsln_x=NP_NN&msbdy=1856&msypn__ftp=Montana%2c+USA&msypn=29&msypn_PInfo=5-%7c0%7c1652393%7c0%7c2%7c3248%7c29%7c0%7c0%7c0%7c0%7c&cpxt=0&catBucket=rstp&uidh=fd7&_83004003-n_xcl=f&cp=0&pcat=ROOT_CATEGORY&h=113462795&db=1930usfedcen&indiv=1&ml_rpos=2

First use of Bly surname so far is 1902 homestead by Andrew.

http://search.ancestry.com/cgi-bin/sse.dll?rank=1&new=1&MSAV=1&gss=angs-g&gsfn=Andrew&gsfn_x=NP_NN_NIC&gsln=Bly&gsln_x=NP_NN&msbdy=1856&msypn__ftp=Montana%2c+USA&msypn=29&msypn_PInfo=5-%7c0%7c1652393%7c0%7c2%7c3248%7c29%7c0%7c0%7c0%7c0%7c&cpxt=0&catBucket=rstp&uidh=fd7&_83004003-n_xcl=f&cp=0&pcat=ROOT_CATEGORY&h=543267&recoff=7+8+9&db=mtdeath89&indiv=1&ml_rpos=12