Search “is Yosemite National Park open” this week and you’ll find a wire story that’s maybe six hours old, still updating in real time. The Colorado Fire ignited Tuesday afternoon, September 1, and by evening it had closed one of the main roads into Yosemite National Park — two days before Labor Day weekend, historically the single busiest travel weekend of the year here. That timing is the whole story. This isn’t a slow-burning backcountry fire like the ones that have shut down corners of Mount Rainier and North Cascades all month. It’s brand new, 0% contained, and it landed on the exact weekend when Yosemite Valley usually can’t hold another car.

Short version: the park itself is fine. Highway 140 is not. Here’s what that actually means if you’re driving up this weekend.

Quick Verdict: Yosemite National Park, Sept. 2, 2026

Area	Status
Yosemite National Park (overall)	Open — not threatened by the fire
South Entrance (Highway 41, from Fresno/Oakhurst)	Open
Big Oak Flat Entrance (Highway 120, from the west)	Open
Tioga Pass Entrance (Highway 120, from the east)	Open
Hetch Hetchy Entrance	Open
Arch Rock Entrance / Highway 140	Closed, Briceburg Bridge to the Yosemite Bug Hostel
YARTS Highway 140 bus route	Runs directly through the closure zone — confirm before relying on it
Colorado Fire size / containment	250 acres (as of 5pm Tuesday), 0% contained

In one sentence: Yosemite National Park is open and isn’t threatened by the Colorado Fire, but the fire has closed Highway 140 — one of only a few paved routes into the park — two days before the busiest travel weekend of the year.

What’s Actually Burning

One fire, one very specific cause, and it’s still young enough that the numbers below will be outdated by the time you read this.

Around 1:23pm on Tuesday, a cement truck crossed lanes on a curve of Highway 140 near Bull Creek Road, roughly 10 miles west of the park, and collided with a small tour bus. The crash sparked a fire in the roadside vegetation. By 3:15pm it had reached 171 acres. By 5pm, 250 acres, still 0% contained. Cal Fire assigned 126 firefighters, 14 engines, four helicopters, and two bulldozers to it within the first few hours — a fast, heavy response for a fire that size, which tells you crews were treating the terrain and the timing as seriously as the acreage.

Highway 140 closed from the Briceburg Bridge to the Yosemite Bug Hostel, the stretch that runs closest to the fire. Mandatory evacuation orders went out for Mariposa County zones 546, 548, and 549, plus Rancheria Creek Road, every campground in Briceburg, and the Octagon area. Zone 547 got an evacuation warning — a step below mandatory, but the kind of notice that means pack a bag and watch the fire’s next update closely.

None of that touches the park boundary. Yosemite itself is not under evacuation, and as of Tuesday evening the fire wasn’t listed as a threat to anything inside the park. What it threatens is the road.

Is Yosemite National Park Open Right Now?

1. Yes, the park is open. Yosemite National Park is not closed, and the Colorado Fire isn’t currently burning toward anything inside the park boundary.
2. Yes, three of the four other entrances are open. The South Entrance off Highway 41 (the route from Fresno and Oakhurst), Big Oak Flat off Highway 120 from the west, and Hetch Hetchy are all unaffected. Tioga Pass, the Highway 120 entrance from the east, is open too, though it’s a seasonal high-elevation road that’s always worth a weather check regardless of fire activity.
3. No, not the Arch Rock Entrance. Highway 140 is closed from the Briceburg Bridge to the Yosemite Bug Hostel — the section closest to the fire, and the one most Central Valley and Bay Area drivers default to.
4. No, not reliably, for YARTS riders on the Highway 140 route. That bus line runs from Merced through Mariposa and El Portal along the exact corridor that’s now closed. If your plan was the bus from Merced, don’t assume it’s running as scheduled — check yarts.com before you show up at the stop.
5. No, not for Briceburg or the surrounding evacuation zones. Every campground in Briceburg is under mandatory evacuation, along with Rancheria Creek Road and the Octagon area. Zone 547 is under an evacuation warning.

Check Cal Fire’s incident page for the Colorado Fire before you leave — a fire at 0% containment on day one moves fast, and acreage figures from Tuesday evening won’t hold for long. The park’s own current conditions page is the second page worth trusting over any single article, including this one.

Why This One’s Different From the Others This Month

This is the fourth “is [park] open” post we’ve written in a week — Mount Rainier, the Everglades, North Cascades, now Yosemite. The pattern across those three was the same: a park that’s mostly fine, with a specific, significant chunk of it that isn’t, and containment numbers crawling upward over weeks.

Yosemite breaks that pattern in two ways. First, the fire isn’t inside the park and isn’t threatening it — this is an access problem, not a resource problem. Nothing about Half Dome, the Valley floor, Glacier Point, or any trail changes because of the Colorado Fire. Second, this fire started yesterday. Rainier’s fires were three and six weeks old when we wrote about them. North Cascades’ fires had been burning since July. The Colorado Fire is hours old at publication, sitting at 0% containment, which means the acreage and closure boundaries in this article are a snapshot, not a settled picture.

Add Labor Day weekend on top of that and you get the real complication. Yosemite Valley parking already fills by 8 or 9am on a normal summer weekend — Labor Day is typically worse, not better, since it’s the last big push before school schedules take over. Losing one of four entrance routes two days before that weekend doesn’t close the park, but it does funnel more traffic onto Highways 41 and 120, at the exact moment those roads were already going to be busy.

What This Means If You’re Planning a Visit

A few things worth doing before you get in the car:

• If you were routing through Highway 140 — from Merced, Mariposa, or the Central Valley on that corridor — reroute now. Highway 41 from Fresno or Highway 120 from the Bay Area side are your options, and both are longer detours than most people plan for on short notice.
• If you booked YARTS from Merced, call or check the website before you drive to the stop. The Highway 140 route runs straight through the closed section; a bus that can’t reach El Portal isn’t getting you into the park.
• If you’re staying in Mariposa, Midpines, or El Portal, check your specific address against the evacuation zone map, not just this article. Zones 546, 548, and 549 are under mandatory evacuation; 547 is a warning zone. Lodging outside those zones should be unaffected, but “should be” isn’t the same as confirmed.
• Expect heavier traffic on the South and Big Oak Flat entrances than usual for a normal Labor Day weekend, since some share of Highway 140 traffic is now rerouting onto them. Arrive earlier than you would have otherwise.
• If Half Dome is on your itinerary, none of this touches the permit lottery — that’s still running on its normal daily Recreation.gov schedule, independent of which entrance you use to get into the park.
• Recheck the Cal Fire incident page the morning you leave. A fire at 0% containment can grow, shrink, or get contained fast in the first 48 hours — Tuesday evening’s numbers are not a safe assumption for Thursday.

This is the same lesson Mount Rainier, the Everglades, and North Cascades have all carried this month: “open” and “unaffected” aren’t the same word, and the gap between them is exactly the part a headline skips.

Planning Around It

If you’re still deciding whether to go this weekend, here’s the actual tradeoff.

Go ahead and plan if: you’re entering via Highway 41 or Highway 120, staying outside the Mariposa evacuation zones, and comfortable with a Labor Day weekend that was already going to mean early arrivals and full parking lots regardless of any fire.

Reconsider or reroute if: your plan depended specifically on Highway 140, the YARTS bus from Merced, or lodging in Briceburg, Midpines, or the Mariposa evacuation zones. Any of those need a real Plan B, not a wait-and-see.

Either way: this is a fast-moving, hours-old fire, not a weeks-old settled situation. Check both the Cal Fire incident page and the park’s conditions page again the morning you leave — not the night before, not this article from Wednesday. For budgeting the trip itself once you’ve settled the route, the affordable bucket list guide covers how to plan a national park visit without assuming every logistics detail holds from one week to the next.

The Bottom Line

Yosemite National Park is open. The Colorado Fire, sparked by a cement truck and tour bus collision on Highway 140 Tuesday afternoon, isn’t threatening anything inside the park boundary — it’s burning outside it, in Mariposa County. What it has done is close Highway 140 from Briceburg Bridge to the Yosemite Bug Hostel, trigger mandatory evacuations in three Mariposa zones plus Briceburg’s campgrounds and the Octagon area, and put a wrinkle in Labor Day weekend traffic for anyone who planned to enter through the park’s western corridor. Three of the four other entrances — South, Big Oak Flat, and Hetch Hetchy — are unaffected, and Tioga Pass remains open on its usual seasonal basis. At 0% containment less than a day in, this is still moving. Check the fire’s own incident page and the park’s conditions page the morning you leave, and route around Highway 140 rather than through it this weekend.

---

Fire details per Cal Fire’s Colorado Fire incident page. Additional reporting per The Press Democrat/AP, GV Wire, and CBS News Sacramento. Entrance and access details per Yosemite National Park’s current conditions page. Information current as of the evening of Sept. 1, 2026 — confirm status against Cal Fire’s incident page and the park’s own conditions page before you drive up.