In 1870 census, there is Knut Espeseth (age 48) with wife, Mari, and 8 children, in Norway Lake Twp., Monongalia County, MN, with a son Knut. First names indexed as "Kunt" and "Kuner"! There is Knud Espeseth, NLT, indexed as Kund, in the 1870 agricultural schedule.
As far as the BLM records go, it is tough to search on names because of the wide variety of spellings used, and the BLM doesn't have a "soundex" type of search. It does have a "wildcard" search, as described here:http://www.glorecords.blm.gov/PatentSearch/Help/SearchTips.a...
If you go to the basic search page, and click on the "standard" tab, you will have many more options, which include searching "all states", or only a state, county, township or section, or searching only by date or transaction type.
In the standard search, you can enter 122N for township, 36W for range (Norway Lake Twp), then hit "search". You will have a list with a link for each result. Click on the "printer friendly" link near top of page and you will see all of the results in a name list that includes:
KNUDSON, KNUDT MN Kandiyohi 1/15/1875 Litchfield 2265 MN0150__.194
Click back, then go to page 2 and click on Knudt's name link; you will find this is a land grant (under "authority") for section 26.
Searching in Arctander, 121N, 36W, gives:
KNUTSON, KNUT MN Kandiyohi 4/10/1866 St. Cloud 2303 MN1580__.395
This is section 1. Click on doc. image, and you see the grant is to KK, of Rice County, authority is cash sale, under law of 1820).
Searching all of Minnesota for 1868 gives a lot of hits with the July 1868 date, which include a
KNUDT KNUDTSEN in Renville/Redwood County (114N, 37W). This appears to have been a sale of Sioux Indian land.
Have you done census searches, know where your people lived?
More here; good link at bottom of the page:http://www.pressenter.com/~gregboe/kandiyohi_county.htm
I've done a lot of searching in Norway Lake, and it seems most folks used the patronym prior to 1880, and the gard name thereafter. Good luck.