The following is a posting I made to OBOL in 2011:
Ok, what that really means is that my Spotted Sandpiper from yesterday was the 100th bird species recorded at Emma Jones since I started visiting the place in August 2009. That's a heck of a lot of birds for such a small place nestled into the suburban neighborhoods on the west side of the Hillsboro Airport.
Time has come to give some details about what I learned from my last 50+ visits over the last 1.5+ years. The writeup below can be used as a site guide for Emma Jones.
First, where is it? Google "Glencoe Creek Park, Hillsboro, OR" which is located at the NW corner of NE 15th Ave and NE Prahl Pkwy. Parking is available at the lot on the north side of this tiny little park. The park itself is not interesting for birds, but there is a fence at the northern edge of the park which, about 40yds in (west) from NE 15th hosts the gate that gets you into Emma Jones Nature Preserve. There is a sign asking to call a City of Hillsboro number to get access. Well, I did call - on behalf of the birding community - and found out that access is granted. There is no official trail system and nothing is maintained for public access. There also are no facilities of any kind. But access is granted. Note that I was warned of uneven ground, Bald-faced Hornet nests in summer and standing water/mud throughout most of the year. This last fact is why you should bring rubber boots for a visit between October and May.
Once you have passed through the gate, follow the two-track west for about 300yds and carefully bird the willows on its north side. This is where most of the migrants will show up in the park. Wilson's, Orange-crowned and Yellow-rumped Warblers are pretty much guaranteed during migration season from end of April to the beginning of June. This particular area is one of the best places in the county for Yellow Warbler in fall (September), with a high count of 6 birds one day. An American Redstart, a first confirmed county record, showed up in the willows in early September '09. A Dusky Flycatcher was found there on April 29, 2010. Lincoln's Sparrow, Warbling Vireo, Western Tanager and Willow Flycatcher are all possible. Thrushes like the willows as well, with Varied, Hermit and Swainson's all occurring in the right season.
The track closely borders a 5ft rock wall on the south side which is good for Pacific Wren in winter and some houses have feeders which should be watched. Just north of the willows runs McKay Creek and it's worth peeking through the willows once in the while. An American Bittern spent 4 days along the creek there in fall '10.
After about 250yds, the area to the north of the track will open up and a pond will appear on the north side. This pond often holds Hooded Mergansers in winter. Continue on the track until you hit a large Weeping Willow. This is "The Narrows" as there is now also a pond on the south side and you will pass right between them on a little dike. Belted Kingfisher and Green Heron like this area and I've seen Wilson's Snipe there when it is muddy in the winter season. This is where the 2-track ends. Nevertheless, don't stop now, but turn right here and proceed in the general direction of a grove of oaks for another about 200yds.
In about 50yds or so, you will enter a shrubby area and several short conifers that can host a lot of surprises. The feeders at the house to the south are usually harboring a good size flock of Golden-crowned Sparrows in the winter season. This is also the area where a White-throated Sparrow was seen twice in the winter of '10/11. In spring, Purple Finches can sometimes be found singing in this area. American Goldfinches love this area and will be present in the summer. A pair of Black-headed Grosbeaks is usually also around in spring/summer. A mimosa in the yard adjacent to the yard with the feeders usually attracts lots of hummingbirds in late summer. The marshy area just to the north of the brushy area has had Sora. The pond to the northwest is the largest at Emma Jones and can hold a good number of ducks, including a year-round contingent of Cinnamon Teal. Common Teal have occurred here among the Green-wingeds. A well-photographed Eared Grebe spent a day on the big pond in October 2010. Great Egrets like to visit the area occasionally in late fall.
As you proceed further along the well-trodden foot trail, carefully check out the access points to the pond's edge. The oak grove now to the north of where you are standing has Western Wood-Pewee in summer and a noisy family of Acorn Woodpeckers year-round. The granary trees can easily be located from across the pond. The snags of the oak grove can host Olive-sided Flycatcher in migration and Merlin in winter. Red-tailed Hawks can often be seen perched up on the tips of the oaks or patrolling the area overhead.
Continue another 50 more yards and you are on the west end of the pond to the north; the trail ends here. There is another feeder on the last house to the south which can be good for Pine Siskin and Evening Grosbeak. The taller trees along the creek and the wide mix of bushes provide good habitat of a lot of different species. Nuthatches can sometimes be heard from here and there always seem to be a few sparrows in the brush. The 4 ponds at Emma Jones are very interesting to dragon and damselflies in the warmer months, in particular when the temperature heats up during the day. Being a relative rookie at odonate identification, I was able to confirm 15 species there in 2010. The best spot is probably at the water's edge right here where the trail ends.
Once back at the parking lot, cross NE 15th Ave and quickly check the pond. The traffic noise can be bad here. Canvasback can show up here in fall and there typically are 5-7 species of waterfowl present during the winter season. A Black Phoebe set up shop here for almost 3 weeks in September 2010. Swallows are usually easy to watch here, mostly including Barn and Violet-Green, but watch for the occasional Cliff and Northern Rough-winged. Killdeer breed on the Intel gravel lot to the west of the pond.
Let me know what you see if you go. Contact Stefan at firstname.lastname@example.org for questions, comments and reports of uncommon birds for the site. The checklist for the park is on eBird.