Portlanders love their parks, and they love their dogs, so it's no surprise that the two would go together. Bring your four-legged friend to the dog run and do a little geocaching at the same time. A dog on a leash could make for excellent camouflage during your search, but isn't required.
Because this is a public park, this can be a high muggle area, so stealth will often be required. You may need patience as the tall trees in the area may cause signal bounce.
Cache is a nano, so it is definitely BYO writing instrument. Please observe park hours and replace the cache carefully so others can enjoy.