The Great Cow Harbor 10K is sold out. Not filling up, not nearly full. The race organization has posted it plainly on its own site, six weeks ahead of the start.

If you were planning to run Northport on September 19 and had not registered, that decision has been made for you.

What is worth knowing is that the race is the smaller half of the weekend, and the larger half costs nothing.

Saturday: the race you are now watching

The 10K runs Saturday, September 19. The elite women and elite men go off at 8:30 a.m. from the start line in front of the William J. Brosnan Building on Laurel Avenue, and the awards ceremony follows at 10:30 a.m. in Cow Harbor Park.

The elite field is the part that surprises people who assume this is an ordinary village road race. The prize purse is $17,250 per gender. The qualifying standards to be considered elite are under 33 minutes 30 seconds for women and under 30 minutes for men, which are times that put a runner in serious national company.

That combination, a small harbor village with a purse that size, is why Cow Harbor draws people who have no other reason to be in Northport in September. A 2K fun run and walk shares the morning.

Spectating is free, and a sold-out field means the course will be worth standing on. The route's reputation rests on one hill, and locals will tell you about it without being asked.

Sunday: the part with room

Cow Harbor Day is Sunday, September 20, from noon to 5 p.m. in Northport Village. This year's theme is a celebration of America's 250th birthday, which is going to shape a lot of Long Island programming over the next year and lands early here.

The parade steps off at noon from the Brosnan Administration Building on Laurel Avenue and runs down Main Street to Woodbine Avenue, roughly three quarters of a mile. That is a short parade route by Long Island standards, which is a feature rather than a limitation: it concentrates the crowd instead of stringing it thin.

From 1 to 5 p.m., Northport Village Park holds artisan and business vendors and non-profit groups, with music in the gazebo, food in the parking lot and rides and games in the adjacent lot.

The boat race, and the thing you can still enter

At 2 p.m. the Crazy Boat Race runs at the Northport Village Dock, from the south end of the dock to the north end.

The rules are exactly as serious as the name suggests, with one exception that is not a joke: participants must wear a certified flotation lifejacket. Homemade vessels and cold harbor water do not care how funny the boat is.

This is the one part of the weekend still genuinely open. As of now the organizers have posted that the application link is coming soon, with questions directed to the boat race chairman. If you want in, that is the page to watch, and the lead time for building something that floats and looks ridiculous is not generous.

Planning around it

Two closures of Main Street in a single weekend is a lot for a village of Northport's size, and anyone who lives there knows the drill. Anyone who does not should plan to park well back from the harbor and walk in on both days.

A few details are not published and should not be guessed at. Race entry fees are no longer displayed now that registration has closed, and the field caps that circulate in conversation are not confirmed on the race site. None of that affects a spectator.

What a sold-out race six weeks out really tells you is about next year. If you want to run Cow Harbor in 2027, the lesson of 2026 is that waiting until Labor Day is waiting too long.