Shamrock Run returns to downtown and Southwest Portland Sunday, prompting early road closures and transit changes

Large running event set for March 15, 2026

Runners are scheduled to take over portions of downtown Portland and Southwest Portland early Sunday, March 15, 2026, as the annual Shamrock Run Fest stages multiple races that use major corridors near Waterfront Park and into the hills above the city.

The event is centered on Southwest Naito Parkway near Waterfront Park, with race activity beginning in the morning and concluding around early afternoon. Organizers have advised that traffic controls will start well before the first start, with some lane and street restrictions beginning as early as 3 a.m. The most significant impacts are expected to continue until roughly 1:15 p.m.

Where runners will be and why the footprint is wide

The Shamrock Run typically draws participants across several distances, including a half marathon and shorter races, which expands the area requiring traffic management. Route materials and past course documentation show the longer distances extending beyond downtown into Southwest Portland, including segments on or near Terwilliger Parkway, before returning to the downtown riverfront for the finish.

Because the start-and-finish area sits near key north-south connections, even partial closures can affect access to the central city. Naito Parkway functions as a primary downtown arterial and is also a frequent access route for parking facilities and bridges. Event operations near the start and finish can also create intermittent crossing limitations for people traveling on foot or by car between the riverfront and the downtown core.

Road closures and mobility impacts expected Sunday morning

Published race-day guidance indicates a major closure along Southwest Naito Parkway between Northwest Davis Street and Southwest Jefferson Street from approximately 3:00 a.m. to 1:15 p.m. Drivers should anticipate additional short-duration restrictions and traffic control points as runners move through downtown and into Southwest Portland.

• Primary closure: SW Naito Parkway (NW Davis St to SW Jefferson St), approximately 3:00 a.m. to 1:15 p.m.

• Timing: Morning starts, with event activity expected to wind down around early afternoon.

• Geography: Downtown riverfront staging with course segments extending into Southwest Portland for longer distances.

Public transit and access to the city center

Major events in the Naito Parkway corridor can also affect bus operations serving the downtown transit mall and riverfront stops. Riders should expect detours or stop closures in the immediate Waterfront Park area during the closure window and allow extra time for transfers and walking connections to the start/finish zone.

Street restrictions are scheduled to begin before dawn and may continue into early afternoon as multiple races start and finish near Waterfront Park.

What to plan for

People traveling into downtown Portland Sunday morning—whether driving, using transit, or arranging ride-hailing—should anticipate delayed access near the riverfront and consider approaching from outside the closure area. Those heading to Southwest Portland destinations along the course footprint may see intermittent restrictions as runners pass.

Race-day operations are expected to be concentrated along Naito Parkway and adjacent downtown streets, with broader impacts tied to the longer courses that head into Southwest Portland before returning to the waterfront.