This ArcGIS map has some functionality built into it.
Click on ArcGIS to open the map in ArcGIS.com
Click on Bookmarks on the upper menu bar to center the Tualatin Watershed on the screen.
The Tualatin Watershed is outlined in dark green. The red pins are projects that have been written up on this web site.
The map opens on Streets.
The slide bar on the upper right size allows you to zoom in and out.