I lived in aspen for 3 1/2 years. cant wait to get back there. i never detected while i lived there but i did explore a lot.
As far as md ing in town, that might be tough. everything is either private or a historic site.
I would recommend going outside of town.
1. There is a road that you can drive up on aspen mountain that will take you to the top and all the way back to taylor pass, called richmond hill rd. there was another town higher on aspen mountain that the road goes by. there is only a restaurant in the area now but it might be a good spot.
2. Head up smmugler mountain rd., opposite aspen mountain, you will see the road going up the side of the hill (east end of town). drive all the way to the top( a little rocky just before) where it levels off and walk a little north, there was some mining back there.
3. follow castle creek rd. back towards ashcroft. i recommend going all the way to the end of the pavement, about 12 miles, just for the scenery. all along castle creek rd are pull offs and a few dirt roads. there were two towns in between aspen and ashcroft along this rd. you will see many places to look around at.
4. go through woody creek, its a small town just before the airport, and follow woody creek rd.back to the town of lenado, about 8 miles back. It is almost a ghost town. you might find some areas to explore around it.
GL and enjoy it there