The proper name for this place is the Weldon Spring Site Remedial Action Project (WSSRAP). In the 40s, the site was used to manufacture explosives. In the 50s, it was used to process uranium ore ("yellow cake") and a nearby quarry was used to dispose of radioactive waste. In the 60s, the Army used the site to manufacture Agent Orange. In the 70s the army used the site for military training. In the 80s the Department of Energy took over and started the cleanup process, and cleanup continued through the 90s. By 2001, the toxic stew was piled up and buried under what I like to call a Post-Apocalyptic Cahokia Mound and then a museum was built to tell us all about radiation and 21st century mound building.
I think my museum friends would agree that this museum is very well done. It's professional and informative and has lots of interesting artifacts. Unfortunately I was so weirded out at being in a nuclear waste museum that while I took pictures, I didn't absorb a whole lot of information.
Think about it: this site was used to make dynamite, uranium, and Agent Orange, three things I think most people have been conditioned to think of as Very Bad. And now it is a Museum and Adventure Trail. WEIRD.
You probably can't read the sign in the picture, so in response to the question, "How much radiation am I receiving at the WSSRAP?" the answer is, "Not much." Less than your average day-to-day activities, presumably because they did such a good job of mound building. Now that we're confident on that point, let's check out the mound.
Now, you might think this is just a mound, that you can maybe walk around it at the bottom and that's it. But just like the Big Mound at Cahokia, there are stairs up to a viewing platform. From this point, I'll let the pictures talk because I just can't describe it.
We walked around the mound after we went to the top, and based on the time it took us we guess it is a little over a mile around.
This is one particular adventure I would recommend to sci fi fans. There's a movie idea here, I'm sure of it.
The directions I got were crap (it took 2 hours for us to find the place) so I will tell you the easiest way to get there from the St Louis area: Highway 40 to State Highway 94 and TURN LEFT. I just Google mapped it again, thinking I must have done something wrong the first time, and the address on the government's website sends you to somewhere halfway between 40 and 70 on 94 and THIS IS WRONG. Trust me. It's south of 40 between the Busch Wildlife Area and the Weldon Spring Wildlife Area. For cyclists, the WSSRAP is on the Hamburg Trail, which intersects the Katy Trail at mile 56.7 just west of the Weldon Spring Trailhead. The Interpretive Center is about 4 miles from the Katy Trail on the Hamburg Trail.