Los Angeles to Mammoth road conditions: US-395 chain controls

From Los Angeles, the drive to Mammoth is CA-14 or I-15 to US-395, then north through the Owens Valley. Chain controls are rare on the valley floor and common on the climb north of Bishop and on SR-203 into town. The US-395 and Mammoth chips above show today's status.

The route: CA-14 or I-15, then US-395

There is one road to Mammoth from Southern California, and two ways to reach it:

• CA-14 from the San Fernando Valley and Santa Clarita, through Palmdale, Lancaster and Mojave, north to US-395.
• I-15 over Cajon Pass from the Inland Empire to US-395 near Victorville, then north through Kramer Junction and Johannesburg. Cajon Pass has its own page, I-15.

The two meet in the desert south of Little Lake. From there it is US-395 past Olancha, Lone Pine, Independence and Big Pine to Bishop, then the long climb past Tom's Place and Crowley Lake to the SR-203 junction, and SR-203 through the town of Mammoth Lakes. June Mountain is farther north: stay on US-395 over Deadman Summit to the June Lake Loop, SR-158.

In dry weather it is roughly five to six hours from Los Angeles, depending on where you start and how the traffic is leaving town. Towns are far apart once you are past Mojave, so keep the tank full; a closure on the summits can mean a long wait in the cold.

Where chain controls go up on US-395

Caltrans District 9 in Bishop posts the controls, and the US-395 page lists every checkpoint with its level, refreshed every 3 minutes.

• The valley floor, Little Lake to Bishop. Rarely under control. The sun dries it quickly between storms, and it is common to drive up from Lone Pine under R-0.
• The climb north of Bishop. The checkpoints run Gorge Road, 16 miles north of Bishop, Sandshed, Windmill, Tom's Place, Crowley Lake, Benton Crossing Road and Sherwin Creek Road. This is the Sherwin grade, up out of the Owens Valley to Sherwin Summit near Tom's Place, and it is usually the first control drivers from the south meet.
• SR-203 into Mammoth Lakes and up to Main Lodge. The most frequently controlled stretch of the trip, and the last to clear. On storm days the checkpoint at the bottom of Minaret Road turns around cars without chains. The SR-203 page lists its checkpoints from the US-395 junction to Main Lodge.
• North of town, for June Mountain. Deadman Summit between the Mammoth and June Lake junctions, then SR-158 itself (SR-158 page).

Eastern Sierra storms bring wind as well as snow, and ground blizzards on the open summits can close US-395 even when total snowfall is modest; Caltrans holds traffic at Bishop, Lee Vining or Bridgeport when the summits are blocked. US-395 checkpoints often have no chain installers, so know how to put on chains yourself and practice before the trip. The Mammoth chain control guide covers the routes from the north as well.

How long is the drive right now?

Open the Mammoth page and use the "via" pill at the top to choose the northbound US-395 route from the south. The travel-time card shows the current drive time on US-395 from Johannesburg to Mammoth and whether traffic is typical or heavier than usual, which covers the desert and the climb but not your drive out of Los Angeles. Tap the card's location button for the time from where you are. CHP incidents near the route are listed underneath.

Cameras and message signs along US-395

On the route from the south the Mammoth page shows cameras at the Coso rest area, Tom's Place, Crowley Lake and McGee Creek Road, and message signs at Brady's junction, Bishop and Crowley Lake. Tom's Place and Crowley Lake are the ones to study: they show whether the Sherwin grade is wet, white or dry. Some checkpoint rows add a Caltrans road-weather station reading with the air temperature and, when it is not dry, the pavement state. The page also carries Mammoth's own webcams of the Village, Canyon Lodge, Eagle Lodge and the summit, a good read on how much new snow you are driving into.

Reading the forecast for a long drive

A six-hour drive means the weather at the bottom of the Sherwin grade can be quite different by the time you get there. On the Mammoth page, the Chains outlook row under the current status gives the forecast for the selected route in a sentence, with seven day chips; tap your travel day, or two days for a range of up to three, for the chance of chains on that trip, and open "Next 72 hours" for an hour-by-hour view. It is a Snowy Roads forecast built from weather data, not a Caltrans notice, and it is shown only where the forecast covers the route well, so on the long desert route it may be missing. The weather card always has the expected snow and rain at Mammoth for three days plus any National Weather Service alerts, such as a winter storm warning.

If a storm is due on your travel day, the safest plan is usually to reach Bishop early and do the climb in daylight, or to wait a day. Requirements change without notice. Caltrans QuickMap (quickmap.dot.ca.gov) and 1-800-427-7623 are the official sources. Always carry chains: under R-2 a 4WD or AWD vehicle with snow-tread tires on all four wheels is exempt but must carry them, and under R-3 everyone chains up. See chains for AWD, 4WD and snow tires.

Get an alert instead of checking repeatedly

You cannot see Sherwin Summit from Los Angeles, and checking every hour from the car is not a plan. The iPhone app knows what you drive, tells you whether you need chains on your route under the level posted now, and notifies you when a control goes up or comes down on US-395 or SR-203. Widgets keep the route on your home screen, with cameras, message signs and travel time a tap away. See US-395 and Mammoth chain control alerts on iPhone.