Where the heck is Wall Drug?

Sweet Jesus! After having picked up today's mailbag at Tom-Tom Tinglit's General but often Strangely Specific Store in beautiful downtown Uranium City, right next to the Uran-o-Seum, what did I discover but another missive from our roving reporter, Lynn Nelson. He is still underway on the Great American Summer Vacation. Lynn writes:

Dear Defensemaster,

Just checking in with you. Yesterday we did Bear Country USA and Wall Drug. Bear country was very interesting. It's a car drive around a road where you experience free roaming animals of the wild...like bears, mountain goats, and donkeys. On our way back we stopped at Wall Drug in Wall South Dakota which is to the best of my ability to explain sort of a old fashioned mall with an interesting history that begins in 1931. It had that silver dollar city feeling, but it only covered about a city block. btw, I've never been to silverdollar city. We are flying out at 5 3o or so.

-Lynn