Cooper Mountain might be another typical urban activation as at first glance nearby Cooper Mountain Nature Park looks like the perfect place to activate --- but it's not actually in the activation zone. There are alternative spots - one across the street from the summit on a sidewalk and perhaps the best at nearby Winkelman Park (see the trip report).

The summit itself is on private property for the area water provider and is posted "No Trespassing." Cooper Mountain Nature Park is on the other side of a saddle and so is not technically in the activation zone. But across SW Kemmer Road is a "greenway" a few yards east of the summit - there is a bark and grass pathway through this greenway connecting SW Jeremy Street and SW 176th Avenue. Go a few yards up from the path towards Kemmer and you'll have trees for antennas and not disturb the suburban dwellers or path walkers. The aerial view below has the recommended activation site circled in red. Of course, you can also do a sidewalk activation across from the water tower - but that's best for 2m FM with a HT.

Perhaps the best spot in the activation zone is Winkelman Park at 10139 SW 175th Ave, Beaverton. In the very northwest corner near 45.4475° -122.86° past the soccer field, there's a paved path that looks perfect for an HF activation. And there's parking in the Winkelman Park lot (if there are no games going on).

If you want the greenway, access it off of SW 176th Avenue (near the red arrow). There is a bit of QRN from home electronics at this location so you might not be able to hear all Chasers, especially on lower bands.