There are areas of town which I believe could yield silver and perhaps preWWI artifacts. However, the historic district is off limits unless the owner of said property requests permission. I've already found out what happens if you don't! The same for the airport area even if the city owns the property.
As some may know, Roswell, suffered a flood ≈18 months ago, which all but ruined the oldest park in Roswell, aka Cahoon Park. The Spring River runs directly through the park. Perviously, you could scan the river beds as there was a walkway along side it. That is now well marked no trespassing. Supposedly, this is because the flood caused contaminates to accumulate in the river bed.
I've been here in the area since 2001, and have scanned most of the available areas, including several ghost towns close to Roswell. And, some of the older homesteads when I could get permission. One sticks in my mind, as it was full of rattle snakes! Probably the worst part, all but one other detectorist hasn't expired, and he doesn't hunt anymore. The hobby itself is growing old as we all know.