Google BLM +"land patents." Frank KOTILINEK patented in Buffalo County, Twp. 108-69, Section 32 SW, & Twp. 107-68, Sec. 8 NW.
WW I draft registration shows Frank [Jr.], b. 15 Aug. 1896 [Ancestry].
FamilySearch.org has quite a few people indexed KOTELINCK in Wright Co., MN, 1880.
FamilySearch.org pilot has the 1905 census cards, showing where Frank [Sr.] was in 1905.