Sounds like something in the cucumber family. There are only two species in Washington State in that family that have green, spiny fruit: wild cucumber (Echinocystis lobata) and coastal manroot (Marah oreganus). The Marah has larger fruit, so I reckon it is probably that, but that species is extremely rare in British Columbia, so I wonder if it is also rare in adjacent coastal areas of Washington. If you have pictures of the fruit, leaves, or flowers, that would help.
COASTAL MANROOT
[source: oregonflora.org]
[source: oregonflora.org]
[source: science.halleyhosting.com]
WILD CUCUMBER
[source: biolib.cz]
[source: flora.nhm-wien.ac.at