This is a relatively easy geocache in the Milwaukee River Greenway.
About the Container
You are looking for a camouflaged peanut butter jar. It is large enough to hold small swag and trackable items.
About the Location
This geocache is hidden next to a stone staircase that connects the upper part of the park to the paths that run along the river. I have done 29 minutes of waypoint averaging in total with a Garmin GPS and an external antenna. It turns out that this is a difficult place to get coordinates. The hiding place is about twelve feet away from the landing of the stairs, under the big tree that has been cut down.
There isn't much traffic but people who pass by on the stairs will definitely see you and wonder what you're doing. As always, should you be caught, the Secretary will disavow any knowledge of your actions.
About the Spy Gear
During the mid- to late-20th Century, people built shortwave radios and used them as a hobby. Occasionally they would stumble onto broadcasts where a person read a long series of numbers with no explanation why. Spy agencies around the world used these number stations to communicate with their agents in the field. An agency would encode a message as a series of numbers and broadcast the numbers over long distances with a high-powered antenna. It was easy to tell where the transmission was coming from but there was no way to tell who was receiving it and decoding it. This technique was used by the United States, Cuba, Great Britain, China, Russia, and others. Shortwave radio later fell out of use but some of these stations have endured well into the 21st Century.
About the Nearby Broadcasting Towers
There are six broadcasting towers over 1,000 feet tall along this section of the Milwaukee River. They were all built between 1952 and 1999. The two towers directly across the river from this spot are on land owned by Milwaukee Area Technical College. Both of the towers have distinctive candelabra-style tops.
The tower with two posts at the top was built in 1981 in a collaboration between the college and WVTV (Channel 18). The college operates Milwaukee's public broadcasting stations on Channels 10 and 36 (WMVS and WMVT). At the time, they were broadcasting from the older WITI tower near Capitol Drive. Channel 18 was an independent station then and they had been broadcasting from the top of the Marc Plaza downtown. Since the college owned the land next to the river, the two entities teamed up to build the tower there. For a while this tower hosted Channels 10, 36, and 18, plus some radio stations including 96.5 and 103.7.
The tower with three posts at the top was built in 1999 by American Tower Corporation, which owns broadcasting infrastructure in countries around the world. It's the newest tower in the area. It's also the tallest at 1,212 feet, which is twice as tall as the US Bank Building downtown. When the tower was built, broadcast television stations were about to make the switch from analog to digital and there was some concern that a whole farm of broadcast towers would pop up in the area to support the new digital equipment. This three-post tower was meant to be a "super tower" with enough capacity for all the commercial digital television stations in Southeast Wisconsin. Channels 10, 36, and 18 all moved over to the new tower in 1999. Today the new tower also hosts at least five other television stations. The older tower still broadcasts the radio stations 96.5, 103.7, and 105.7. Channels 10 and 18 have backup antennas on that tower.
Permission
Permission to place this cache has been granted by the Milwaukee County Parks Department. Permit No. 574.