If you live in Broadmoor and you head out the north entrance for your usual loop toward Foster Island, you are going to hit a fence you have not seen before. It is not a permanent one, and it is not bad news exactly, but it changes the walk you have been doing for years, and this is the season to know about it before you lace up.
Every description of Broadmoor mentions, almost as a throwaway line, that the Arboretum functions as the neighborhood's backyard. That is true, but it has always been a little too tidy a phrase. The Arboretum is not just adjacent to Broadmoor. Underneath the golf course, storm drainage actually feeds into the same creek system that runs the Japanese Garden's koi pond. The two properties are connected below the surface, not just across a fence line.
The golf course and the garden share plumbing before they share a name.
That kind of detail matters more this fall than usual, because the easy version of the walk from Broadmoor's north gate is currently interrupted, and the reason is worth understanding before you plan an October evening around it.
What Actually Closed, and Why
Seattle Parks and Recreation began Phase 1 construction on the Washington Park Arboretum Waterfront Trail restoration project in June 2026, with Redside Construction handling the work. The project rebuilds the Foster Island section of the floating boardwalk, the stretch of trail that carries walkers out over Union Bay's wetlands between the Arboretum proper and the totem pole overlook at Marsh Island. The floats, support piles, gangways, and railings are all being replaced, and Seattle Parks does not expect the reopening until early 2027.
That means the portion of the Waterfront Trail nearest Broadmoor's north entry, right around East Foster Island Road, is closed to public access for the rest of this year and into next.
The project is not cheap or improvised. It runs about $2.45 million, funded through three separate sources: $475,000 from the SR 520 bridge mitigation program for design and permitting, $855,000 from the Aquatic Lands Enhancement Account and state trails funding, and $1.12 million from the Seattle Parks District Fund, the same voter-approved levy that pays for park maintenance across the city. More than 1,200 people weighed in during the public survey that helped secure that funding, which tells you this stretch of boardwalk gets used by more than just the households on the Broadmoor side of the fence.
Phase 2, covering the Marsh Island section, is still in design and has not started construction.
The Route That Still Works
None of this closes the Arboretum. It closes one specific waterfront segment. The Loop Trail, a 1.2-mile connector that opened in 2018 and ties into Arboretum Drive East to form a 2.5-mile circuit, stays open and does not depend on the Foster Island boardwalk at all.
If your usual habit has been to exit Broadmoor's north gate and follow Foster Island Road out toward the water, the workaround this season is to head south instead, toward the Graham Visitors Center, and pick up the Loop Trail from there. A few notes on getting oriented:
- Arboretum Drive East runs nearly a mile from Lake Washington Boulevard, across from the Washington Park Playfield, north to East Foster Island Road, just west of Broadmoor's north entrance. Only the northernmost stretch, the part leading into the Graham Visitors Center, has allowed cars for years. Everything south of that has been pedestrian and bike only for over a decade.
- Parking is available at both the Graham Visitors Center lot and the Japanese Garden lot, and either one puts you within a few minutes' walk of the Loop Trail entrance.
- If you're driving in from inside Broadmoor rather than walking, Lake Washington Boulevard to East Foster Island Road to Arboretum Drive East is still the fastest way to the visitors center, even with the boardwalk closure.
It is a longer walk than the direct shot to Foster Island, but it trades a closed dock for a full loop through the parts of the Arboretum that are actually peaking right now.
What You're Walking Into, and Why the Timing Might Move Up
October in the Arboretum means Japanese maples, witch hazels, black gums, sorrel trees, buckeyes, strawberry trees, and mountain ash, according to the University of Washington Botanic Gardens' own seasonal calendar. The Woodland Garden section holds one of the largest collections of Japanese maples in North America, and it is the part of the property that earns the reputation the rest of the Arboretum trades on every fall.
Puget Sound lowlands typically hit peak color in mid to late October, later than the mountains, which usually turn in late September. But this year had an unusually dry, warm summer. Seattle ran about a degree above average for the season, hit 95 degrees on July 22, crossed 90 degrees four separate times, and went 33 days without measurable rain between late July and late August. Moisture stress and heat like that tend to push leaf color earlier rather than later. If you have always timed your Arboretum walk for Halloween week out of habit, this may be the year to move it up toward mid-October instead, rather than assuming the calendar behaves the way it usually does.
The Japanese Garden Runs on Its Own Rules
The Seattle Japanese Garden sits inside the Arboretum's southern end but charges its own admission, separate from the free public grounds around it. Adult entry runs $10, with reduced rates for youth, seniors, and students, and free admission for children five and under. Inside, the autumn tradition is momijigari, maple viewing, when the garden's Japanese and Asiatic maples color in layered combinations that the open Woodland Garden does not quite replicate.
The garden also hosts an annual Moon Viewing event, otsukimi, with lanterns lit along the paths after dark. It has run in early September in recent years, but the exact date shifts with the lunar calendar and had not been posted for 2026 at the time of writing. If that is on your list this fall, it is worth a direct check with the garden rather than assuming last year's weekend repeats.
Where the Walk Ends
The practical version of this loop, for most Broadmoor households, ends the same way it always has: back through the gate, or out toward Madison Park for coffee or dinner. Cactus and The Independent Pizzeria both sit along East Madison, an easy stretch from either Arboretum exit, and Starbucks holds down the corner for anyone who just wants the walk to end in fifteen minutes instead of forty. McGilvra's Bar and Restaurant, a few blocks further at 4234 East Madison Street, is the option when the walk turns into an evening.
None of that changes this fall. What changes is which gate gets you there fastest, and that is the kind of detail that only shows up if you are paying attention to what Seattle Parks is actually building this year, not just what the Arboretum has always looked like.
The Backyard Is Still There, It Just Has a Detour Sign
The claim that Broadmoor backs directly onto one of the country's better public arboretums is not marketing language. It is a fact about drainage, property lines, and a shared creek that predates every home currently standing in the neighborhood. But a backyard with active construction is still a backyard, and the households who know to route around the Foster Island closure this season are going to get more out of October than the ones who show up at the north gate expecting the trail they remember.
If you are already living inside the gates, this is the kind of neighborhood detail that tends to matter more once you have owned here for a while, the same way you eventually learn which HOA meetings matter and which restaurant holds a table on a Friday. Exact Home Team spends a lot of time in Broadmoor, Washington Park, and the rest of the neighborhoods along this side of Lake Washington, and we like knowing this stuff as much as you do. If you ever want to talk through what is happening in the neighborhood, whether that is a construction timeline or a market question that comes up later, Let's Get Started.
