google maps has nice, relatively high res images (some of the highest res you will find in a rural area like this on google maps much less a high pop area) of that entire area from this July (all the areas that have a somewhat bluish tint to them) so you can get a good close view of the surrounding areas too.
Dell Rapids is a nice town but high property taxes. Pretty though. Grocery store that doesn't seem to price gouge too much either like Maynards does. Found some cheap items in it. Most of the town's residential areas are built on hills which is kind of nice, some pretty steep. Nice downtown, although several roads around town including downtown have absurdly low speed limits.
What would be pretty is if they turned that large quarry of theirs into a lake, but I'd imagine they have many years to decades of use left in it.
I wonder how deep the deepest part of it is down.. looking at google maps, there's a sizable drop.. that huge cliff on the south end compared to that small truck sitting there.
Garretson is a nice town close to palasades.. both these are on the outer limits of your 20 mile range.