B.M.
There's a little park off of SW Florence Ln and SW 74th, near Taylor's Ferry Rd in SW Portland, I think it is called Florence Pt Park that has a small sort of wild pond at it. In the late summer there are always lots of baby frogs there, so I'm thinking that there are probably frog eggs in the pond at some point. Maybe tadpoles too? let us know if you find some. =)