Halloweekend Downtown, With Trinity Drive Still Down to One Lane

Trick-or-Treat on MainStreet runs for two hours, from 4 to 6 p.m. on Friday, Oct. 30. Apart from a morning family party, the rest of the Friday program runs from 3 p.m. to 10 p.m. at nearly a dozen sites around the townsite. This year, the main road into downtown is also a construction zone. Under the County's Oct. 19 work plan, Trinity Drive is down to one lane in each direction between Oppenheimer and Knecht, and the project isn't scheduled to finish until Dec. 18.

Those two schedules overlap. Arriving at 4 p.m. means reaching Central Avenue with everyone else, after a drive through a narrowed corridor, while the events before and after the main window let a household arrive early or late and spread the evening out.

A Seven-Hour Friday Evening

After a morning party, Los Alamos MainStreet's 2026 Halloweekend schedule staggers Friday's events from 3 p.m. to 10 p.m. Most of them start before or end after the Central Avenue window.

The main event is big. The Los Alamos Reporter reported that Trick-or-Treat on MainStreet will have more than 75 booths run by local businesses, nonprofits and community groups, plus live dance, local music acts and food trucks. Central Avenue becomes a pedestrian-only zone for "thousands of costumed trick-or-treaters."

The table also shows ways around the crowd. The LAMC trick-or-treat starts an hour before Central Avenue closes to cars. The YMCA session runs until 7 p.m., an hour after the downtown booths close. The After Party at the library picks up at 6 p.m., right as the MainStreet window ends, with s'mores, games and glow jewelry in the area between the library and the senior center. A family could start at the hospital lawn at 3 p.m., walk Central Avenue once the early crowd thins, and end the night at the library without having to arrive at the busiest moment.

PEEC-a-Boo at the Nature Center runs at the same time as MainStreet, 4 to 6 p.m. It's free and designed to be sensory-friendly, so it's a real second option for children who would find a crowded street of 75 booths too much. Planetarium tickets for "Aliens!" at 7 p.m. are listed at $6 per child, $8 per adult and $20 per family.

What the Construction Zone Looks Like Right Now

All of this happens a short distance from the County's Trinity Drive Safety and ADA Improvements project. It's a $6.75 million project, Hasse Contracting Company is the contractor, and work runs along both sides of Trinity.

The County's update dated Oct. 19, covering work through Oct. 23, set the following conditions:

• Eastbound Trinity is down to one lane from Oppenheimer to 20th.
• Westbound Trinity is down to one lane from Knecht to Oppenheimer.
• 20th Street south of Trinity is closed, and the County directs drivers to the driveway to the west.
• Bus stops at Elks Lodge, O'Reilly Auto Parts, Sonic and the Smith's fuel station remain open inside the construction area.
• The Oppenheimer and 20th bus stops are closed.

The same update says crews have finished most of the concrete on the south side except at utility crossings. Gas line relocations are still planned on that side. Crews were also working on the sidewalk from 15th Street to Knecht, while keeping the sidewalk from 15th to 20th open. The County says pedestrians will always have one-way access and that access to every business on both sides of Trinity is being maintained. Bixby Electric, a subcontractor, is wiring the new traffic signal at 20th and Trinity and may close lanes occasionally.

A second project runs alongside it. On the County's alerts and current conditions page, the Trinity Drive Electrical Replacement Project has closed and removed sidewalks on the south side of Trinity from Oppenheimer to Timber Ridge while electrical line and fiber go in. Timber Ridge has no dedicated turn lane, so the County asks drivers not to turn left onto it at busy times and to make right turns only.

Weekly updates have changed lane and stop conditions before, and the plan in place on Oct. 30 may differ from the Oct. 19 version. The County has a project update sign-up for anyone who wants the latest work plan before Friday.

Parking, Bus Stops and the 15th Street Closure

The event adds its own closures. Central Avenue is closed to vehicles during trick-or-treating, and Visit Los Alamos lists 15th Street as closed between Central and Iris from 3 to 7 p.m., a longer window than the booths themselves.

No parking plan specific to Halloweekend has been published. For an August event weekend, the County listed these downtown lots:

1. Municipal Building parking, reached from Central when it's open, or from Iris
2. The Mesa Public Library main lot, reached from Oppenheimer
3. The auxiliary library lot and Betty Ehart lot east of the library, reached from Peach and Bathtub Row
4. Ashley Pond parking, reached from 20th
5. Justice Center parking, reached from Trinity

Since August, some of this has changed. That notice listed the 20th and Trinity bus stop as an open alternate, but the Oct. 19 update lists the stop as closed. The same notice said the library's main lot would close again for construction. Treat the list as the usual options and check each one on the day. The lots reached from Oppenheimer, Peach and Bathtub Row avoid the narrowed section of Trinity. The Justice Center lot is reached through it.

The Bradbury Science Museum has its own parking instruction. MainStreet's schedule asks visitors to "park in the back lot, as there will be a 'treat trail' in the front parking lot."

Atomic City Transit is running reduced service this month. The County's transit page lists adjusted Route 5 service since Oct. 13 because of staff shortages, Route 2M suspended, and some peak trips on Routes 1 and 6 suspended. Route 1 is the Downtown Circulator. No extra service or detour has been announced for Halloweekend. The transit page also says stop conditions in the Trinity work zone can change daily. Near the closed Oppenheimer and 20th stops, it lists the O'Reilly, Timber Ridge, 15th Street and Knecht stops as open.

Saturday Is for Older Kids and Adults

Saturday's events skew older and spread farther from Central Avenue. Some families with young children have a second chance in the morning: Session 2 of the Family Strengths Network Fall Party runs 10 a.m. to noon, and Natural Grocers' Spooktacular Family Fun, with a treasure hunt, crafts, door prizes and treats, runs 11 a.m. to 1 p.m.

The evening events are mostly for teens and adults:

• Pueblo Canyon Inn Haunted Trail, 7 to 9 p.m. at 199 San Ildefonso Road. It's free and run by local teens. The Visit Los Alamos event page describes two paths, one with jump scares and one without. That page lists Friday, Oct. 23, while MainStreet and the Los Alamos Reporter both give Saturday, Oct. 31. Confirm the date with the organizers before you go.
• Brad "Buried" Halloween Bash at the Bradbury Science Museum, 7 to 11 p.m., for ages 18 and up, with dancing, a beer garden, a food truck and horror movies.
• Lights Out in the Bookstore at Samizdat Bookstore & Teahouse, 7 to 9 p.m.
• White Rock Baptist Church's 19th annual Trunk or Treat Fall Festival, 5 to 8 p.m., for families in White Rock who would rather stay close to home.

Saturday also has a "Black Holes" planetarium show at the Nature Center at 11 a.m. and a Halloween Blood Drive with Vitalant at the Teen Center from 2 to 6 p.m. Halloweekend officially runs through Sunday, Nov. 1, but MainStreet's 2026 schedule lists no Sunday events.

What Trinity Gets When the Barrels Come Down

When the Trinity work finishes on its Dec. 18 schedule, the corridor will connect better to Ashley Pond and its events. The County's design adds an 8-foot multiuse path along the south side of Ashley Pond Park from 20th Street to the Justice Center, which the project page says "better serves special events" and connects to the Canyon Rim and Urban trails. The design also adds an NM DOT Park-&-Ride layover pullout on the north side, near the Justice Center parking area.

The planned cross-section shows one car lane and one bike lane in each direction, with a shared turn lane in the middle. This year's Halloweekend will be the last one before those changes are finished.

From Fuller Lodge to the Ashley Pond lawn, the team at Summit Group Real Estate Professionals follows how the Los Alamos townsite is changing street by street, and we're glad to talk about what Trinity Drive and downtown will look like once the work is done. If you're weighing a move within Los Alamos or White Rock, Contact Us.