This Search Engine should cover most of the pages within MNGenweb.

There is a separate Search Engine for the MNArchives on the Minnesota Table of Contents page.

Start with a Surname here and when the search is finished it brings you to a "Pico results page" with a listing of what sites were found and then you can do another search within these "sites found"  to narrow your search by entering a "given name" in the box and clicking the small box to the right "within results".

Good Luck Searching