Reading the live feed from Nevada 511…
Reading the live feed from Nevada 511…
I-15 | Primm to Baker, over Mountain Pass
Mountain Pass conditions, cameras, and posted restrictions will show live here from Nevada 511 the moment the feed is connected. Until then, check Nevada 511 for the official word before you drive.
The summit is in California, and Nevada 511 covers the Nevada approach to the state line only. This page pairs that live Nevada status with the National Weather Service forecast at the summit, so you can judge both the approach and the top of the climb before you leave.
Data: Nevada 511 / NDOT
Most drivers think of the drive from Las Vegas to Southern California as flat desert, and for long stretches it is. Mountain Pass is the exception. West of Primm, Interstate 15 leaves the state line, crosses into California, and climbs in earnest to a summit at 4,730 feet. It is not a pass in the Sierra sense, with pine forest and deep snowpack, but it is a real mountain grade in the middle of the Mojave, and it behaves like one when weather moves in and when summer heat sits on the road down to Baker.
This page exists because that difference surprises people. A clear, warm departure from Las Vegas or Primm can end in wind, cold, and snow at the top less than an hour later, while a winter morning at the summit can give way to a mild, bright run into Baker. Read this page as two checks in one: the live Nevada approach to the state line, and the forecast for the California summit above it.
Mountain Pass summit right now: Mostly Sunny, 57°F.
Mostly sunny. High near 57, with temperatures falling to around 51 in the afternoon. North northeast wind 2 to 6 mph.
Forecast: National Weather Service, for the point itself, not the valley floor.
State line at Primm
Last Nevada services and the start of the California climb, where the live Nevada verdict on this page applies.
Nipton Road exit
A quiet desert exit on the lower climb, useful as a progress marker with no major services to count on.
The long climb
The sustained grade up from the valley floor, where trucks slow, temperatures drop, and winter weather can begin.
Summit and brake check area
The top at 4,730 feet by the rare earth mine, with a brake check area for trucks starting the descent.
Cima Road and the descent to Baker
The long downgrade toward Baker, where heat builds fast and brake discipline matters in both summer and winter.
The numbers explain the feel of the road. From Primm at the state line, the highway climbs about 2,100 feet to the Mountain Pass summit. That gain happens on a sustained interstate grade, not on a short hill, so engines work, trucks drop speed, and passing takes more planning than it does on the flat desert south of Las Vegas. In a passenger car the climb is easy on a clear day, but the length matters. A slow vehicle near the start of the grade will shape traffic for miles, and a mechanical problem that would be minor on flat ground becomes harder to manage on the shoulder of a climb.
The landscape changes with the elevation. The creosote flats around Primm give way to rockier, higher desert, with Joshua trees and open views across the Ivanpah Valley behind you. Temperatures fall as you climb, noticeably in winter and usefully in summer, which is one reason a jacket left in the back seat in Las Vegas can be wanted at a summit stop. Wind also behaves differently up high. Gusts that are a nuisance on the flats can push high profile vehicles around on the exposed upper grade, especially when a front is passing.
Treat the climb as its own segment, not as part of the flat run to California. Check fuel before Primm, because the next dependable services are a long way beyond the summit at Baker. Give trucks room on the right lane and expect speed differences to widen as the grade steepens. If traffic compresses, leave extra following distance, since a loaded truck ahead and a fast car behind is the normal mix here.
It snows on Mountain Pass. At 4,730 feet, the summit sits high enough for Pacific winter storms to drop snow, build ice on bridges and shaded pavement, and cut visibility to near zero in blowing conditions, all while Las Vegas and Baker stay comparatively mild. Snow here is not an every week event, and many winter crossings are bare and dry, but when a storm lines up with the elevation, conditions at the top can change quickly. Caltrans posts chain controls on the California side when conditions require them, and those controls, not the clear road at Primm, are what govern the summit crossing.
The February 2023 storms are the recent reminder most local drivers remember. A series of strong winter systems shut this road and turned a routine interstate drive into a stranded, slow, and difficult trip for many travelers. That kind of closure is uncommon, but it proves the point this page is built on: the summit has a real winter climate of its own. A forecast that only describes Las Vegas, Primm, or Baker will miss it. Cold air pooled at elevation, moisture arriving on southwest winds, and pavement temperatures near freezing are the combination to respect, even late in the season.
Practical winter driving here is mostly preparation. Carry chains or be ready to turn back if controls are posted and you are not equipped, keep the fuel tank well above empty before the climb, and carry water, warm clothing, and a charged phone in case traffic stops on the grade. Slow down early if snow begins, because both grades punish late braking on slick pavement. If the summit forecast shows snow and wind together, consider waiting in Primm or Baker rather than testing the top.
At the top of the climb, on the south side of the highway, sits one of the most unusual industrial sites on any American interstate: the Mountain Pass rare earth mine, operated by MP Materials. It is the only US rare earth mine of its kind, producing materials used in magnets and other technology that most drivers carry in their phones and vehicles without thinking about it. From the highway you see terraced workings, industrial buildings, and the broad footprint of a large open pit operation set in otherwise empty desert. It is a working mine, not a visitor attraction, and there is no public tour stop on the interstate.
The mine gives the summit its identity. Without it, Mountain Pass would be a named high point that most drivers cross without noticing, but the operation and its place in national supply discussions make the top of this grade a location people write about far beyond road conditions. It also explains some of what you see at the summit, including industrial traffic, lighting at night, and the developed area near the brake check. The mine has a long history in this district, and its current operation under MP Materials has returned national attention to this remote stretch of I-15.
For the traveler, the right response is curiosity from the highway and no detours. Do not leave the interstate to explore mine roads, do not stop on the shoulder to take photographs, and do not assume any road near the summit other than the signed exits is public or maintained for passenger cars. Viewed safely from traffic, the mine is a striking contrast: a site of global industrial importance sitting beside a desert highway. It is one more reason this summit feels distinct from every other mile between Las Vegas and Barstow.
Mountain Pass is a truck road as much as a car road. Interstate 15 is a primary freight route between Southern California ports and markets, Las Vegas, Utah, and the interior West, so heavy trucks work this grade in both directions all day and all night. Westbound, that means loaded trucks climbing slowly, sometimes far below the speed of car traffic, with the gap widening near the top. Eastbound, it means trucks managing a long descent where brakes, gearing, and speed discipline decide whether the run down to Primm stays routine. The brake check area at the summit exists for exactly that reason.
For car drivers, the discipline is simple but important. On the climb, expect slow trucks, merge with patience, and avoid sitting in a truck blind spot on the grade where the driver is focused on power and temperature. On the descent, in either direction, use engine braking by shifting to a lower gear on long downgrades rather than riding the brake pedal, which can overheat brakes and fade stopping power before the bottom. If you smell hot brakes in traffic or see a truck trailing smoke, give it wide room and do not follow closely. Runaway problems are rare, but the grade deserves respect.
Heat and grade combine here in a way flat desert driving does not teach. A vehicle with a marginal cooling system may run fine from Las Vegas to Primm and then overheat on the sustained climb, especially in summer with air conditioning running. Watch the temperature gauge on the way up, and use a turnout or exit rather than a narrow shoulder if you must stop. Coming down, a car that feels fine at the summit can still cook its brakes by Baker or Primm if the driver rides them. Steady, early control beats late, hard braking every time.
North of the highway at the summit, Clark Mountain rises to 7,929 feet, the dominant peak in this part of the northern Mojave and far higher than the pass the road crosses. On a clear day it stands over the interstate with a presence that explains the whole geography of the corridor: the highway threads a lower saddle while real high country, with colder temperatures, stronger wind, and winter snow that can linger, sits just beside it. Clark Mountain is a useful visual weather gauge. If its top is in cloud while Primm is clear, conditions at elevation are already different from the valley.
The mountain also puts the pass in perspective. At 4,730 feet, Mountain Pass is high for a desert interstate, but it is more than 3,000 feet below the Clark Mountain summit nearby. That gap is why the road is passable in most winter weather while the peak above holds snow, and why storms can look dramatic overhead yet leave the highway merely wet or briefly snowy. It is also why wind can spill down from high ground and hit the road in gusts. Drivers crossing at night miss much of this, but in daylight the peak, the mine, and the long valley views make this the most scenic segment of the Las Vegas to Barstow run.
There is no interstate access to Clark Mountain itself, and this page does not suggest treating it as a roadside stop. Its role for the traveler is context and warning. Context, because it shows that this is genuine mountain country inserted into a desert drive, not a marketing name on a small hill. Warning, because weather visible on the peak, snow on its upper slopes, or a dark storm base sitting on it, tells you the air at pass level is cold, unstable, or wet before the road itself proves it. Look up as you climb, and let the mountain inform the forecast you already checked.
West of the summit, the road falls toward Baker, and in summer the character of the drive flips from mountain cold to valley heat. Baker sits at the edge of country that leads toward Death Valley, and the valley floors on this side of the pass are among the hottest on the route. Temperatures at Baker routinely run far above those at the summit on the same afternoon, and vehicles that struggled to stay warm enough for traction in winter now face the opposite problem: overheated engines after the climb, stressed tires, and drivers who have been in air conditioning so long they underestimate what stepping out at a Baker stop will feel like. Carry water for people and pets on every summer crossing.
Baker itself is the practical gateway town for this side of the corridor, with fuel, food, and the famous junction toward Death Valley. It is the last sensible place to address a warning light, a soft tire, or a low fuel gauge before committing eastbound to the climb, and the first sensible place westbound to check a vehicle that ran hot or braked hard on the descent. If your vehicle shows any stress on this segment, use Baker or Primm to deal with it rather than hoping the next flat stretch will forgive it. Desert distances punish optimism.
Finally, learn to read this page the way it is built. The live status carried here comes from the Nevada approach, and it tells you whether the Nevada side is flowing, restricted, or troubled before you cross into California. The summit forecast tells you what the top is likely doing now and in the next hours, which is where snow, ice, and the strongest wind will be. Neither source alone is the whole answer for a California summit. Together, a clean approach plus a calm summit forecast means a normal crossing, while either one flashing a warning is reason to slow down, prepare, or wait.
Does it snow on Mountain Pass?
Yes. At 4,730 feet the summit is high enough for winter storms to bring snow, ice, and blowing visibility problems, even on days when Las Vegas, Primm, and Baker are mild. Snow is not constant in winter, and many crossings are dry, but when a storm arrives, Caltrans can post chain controls on the California side and the road can close in the strongest systems, as it did during the February 2023 storms.
How high is Mountain Pass?
The summit is 4,730 feet above sea level. That is about 2,100 feet above Primm at the state line, which is why the climb feels sustained rather than brief. Nearby Clark Mountain is much higher at 7,929 feet, but the interstate crosses the lower pass beside it, not the peak itself.
Is Mountain Pass open right now?
Use the two checks on this page together. The live status shown here is the Nevada 511 verdict for the Nevada approach to the state line, carried from the Primm segment, and the forecast shows conditions at the California summit itself. If the approach is clear and the summit forecast is calm, the crossing is normally open and routine. If either shows snow, restrictions, or a closure warning, treat that as the answer and check official California sources before committing to the climb.
How long is the climb from Primm?
The full corridor on this page runs 63 miles from Primm to Baker and takes about 55 minutes in free flow. The main climb is the rise from Primm at the state line up to the 4,730 foot summit, a gain of about 2,100 feet on a sustained grade. Trucks will be much slower than cars on this section, so free flow times stretch quickly when traffic is heavy or weather slows the grade.
Where are the cameras on this corridor?
Honestly, NDOT cameras end at the state line. Nevada 511 cameras cover the Nevada approach through Primm, and this site shows those Nevada frames. There is no Nevada camera at the California summit, which is why this page pairs the live Nevada approach status and cameras with the National Weather Service forecast point at the summit itself, rather than pretending a camera view exists where it does not.