It is odd that some of the children are using the name Olson with their parents Haugan on the 1900 census. However their 3 younger siblings are Haugan. The kids are the correct age to be those of Lars and Lena. In 1910 ALL of the children are using Hogan as well as the parents.
The 1910 census says that this is the 2nd marriage for Louis and Lena. I can't quite read what the immigration year is in 1910 but it is not 1869 - perhaps 1870 or 1872 though that is often not correct.
I think Taryn is on the right track with the names but I also think some digging needs to be done in Crawford and LaCrosse counties.