About the Container
You are looking for a small black magnetic container. It's too small to hold most travel bugs or trade items. Please bring your own pen.
About the Location
This cache is hidden up on the top of the bridge. You don't need to climb anywhere or go down to the street to find it. This is a pretty safe area but you are on a bridge over a busy street so please be careful and use common sense.
This old railroad bridge was part of the C&NW line. According to a nearby plaque it was built by the Milwaukee Bridge Company in 1936. It must not be the original bridge because the tracks are about fifty years older than that.
Why Does the Bridge Have a Corner in the Middle?
The north half of the bridge was built first and the south half was added later. Originally, two sets of tracks ran through this area side by side. Here is a picture of the bridge from 1967.

Around 1970, Silver Spring Drive was widened from two lanes to four. This picture is from 1970. You can see that the road is torn out and a temporary track has been built on the east side of the bridge.

The railroad must have decided they didn't need two tracks by that time. When the bridge was lengthened to span the new lanes, the new part was only wide enough for one set of tracks. Apparently it wasn't worth the trouble to change the original part of the bridge, so it was left two lanes wide. Here is the finished bridge in 1975.

Thanks go to BBadger who found these aerial pictures and sent them to me.
About the Series
The cache is part of the Oak Leaf Trail series. For information about the whole series, including tips about how to plan your approach, please see the listing for Oak Leaf Trail 01.
Parking
The best parking for this cache is near Oak Leaf Trail 16. Please read that cache page for more details.
Permission
Permission to place this geocache was granted by the Milwaukee County Parks Department. Permit 488.