Parking is fairly limited, although street parking in the area may be
available. There are some *very* busy train tracks between the park
and water. I believe you would need to tresspass to get closer access
to the gull, so don't do that.
Also, it's worth noting that the park is in King County, but from
John's description the bird is in Snohomish County, actually within
spitting distance of the county line. For eBird checklists I believe
the correct protocol would be to make a personal location at the oil
facility to place the bird in the correct county. Perhaps one of our
eBird reviewers would like to make a "stakeout" hotspot at this
location? If it flies south at all today, it'd almost instantly be
back in King Co.
I am not a gull, but the areas around this location would seem to me
to be much better habitat for a species such as this to feed during
the evening. Puget Sound is 600+ft just offshore in this area, and
the triangle between Point No Point, the south tip of Whidbey Island,
and Edmonds has been a traditional hotspot for pelagic species in the
past. It also hosts thousands of gulls most falls.