Elk and moose both will sometimes travel hundreds of miles looking for new territory. There is a herd of elk in Ft. Riley KS and they will wonder away from post several counties, but most of the times they find their way back. Neat creatures to study.
As for the elk in Muscatine by the Cedar, a guy on G28 has Bison and elk only two miles from the river, I’d bet he had one or two get out. I wasn’t around last year to know but I drive by his place to get to my hunting ground.