This is a lovely piece of once intensively-used land in the Snohomish River Estuary that's in the process of reverting to a natural estuarine wetland. Head out for an easy walk (the dike trail is flat and suitable for baby joggers) through pretty terrain, or to spot birds and wildlife. The parking lot lies right next to the Everett Sewage Treatment Plant, making for a rather smelly start. Don't despair, though; leave the lot and walk the flat, roughly 1/4 mile access road that cuts through a wetland. This is a good place to bird - watch for several species of swallow, raptors, marsh wrens, goldfinches, cedar waxwings, and more. It's flat, beautiful, and wild in spite of the traces of human activity all around. Once you reach the island, cross the bridge over the river (in spring and summer, look for cliff swallows in the mudbanks below) and head for the boardwalk straight ahead. There you will find a nice view of the wetland, interpretive signs, and picnic tables. The day we visited, we saw signs of deer in the tall grass surrounding the boardwalk. The trails set off along the slough in both directions. It's flat and easily traversed, but bikes are not permitted on some portions - look for signs. Dogs are also not permitted, since they can disturb wildlife. Again, be on the lookout for birds - Spencer Island is a birding hotspot - and wildlife such as coyote, river otter, and small amphibians. If you go with kids, note that there's little shade along the trail, the only toilets are portable, there's no running water, and the ground can be mucky after rain - it is a wetland, after all. Binoculars are a big help.