Quick Summary:
- Check Caltrans conditions, plan alternate dates, and expect sudden closures.
- Carry correctly sized chains, practise fitting, and follow chain-control rules.
- Fill up early on US-395, stations are sparse after Bishop.
- Pack winter kit, allow extra time, and avoid driving during peak snowfall.
Driving to Mammoth Lakes in winter can be straightforward, or it can turn into a slow, stop start crawl behind ploughs with chain control ahead. If you are using car hire in California, the key is to treat US-395 as a mountain route, not a simple highway run. Weather changes quickly, cell signal can be patchy, and services thin out north of Bishop. This checklist walks you through what to do before you leave, what to carry, where fuel planning matters most, and how to react if roads close.
First, set expectations. Chain controls are common after storms and can apply even when roads look merely wet. Closures do happen, especially around steep sections, high passes, and during active avalanche control. You can still travel safely if you plan for delays, keep your fuel buffer high, and know how to respond when the route is temporarily shut.
Step 1, Confirm your car hire is winter ready
Before you set off, confirm what your hire vehicle is equipped with and what is permitted. In California, many hire cars have all season tyres, not dedicated winter tyres. Even with all season tyres, you can be required to fit chains during chain control. Some hire agreements restrict chain use because incorrect fitting can damage wheel arches or brake lines. Read your rental terms carefully and choose a vehicle with appropriate clearance if you expect heavy snow.
If you are collecting near a major gateway, reviewing pick up options ahead of time helps you match the vehicle to the trip profile. For example, travellers arriving via San Francisco often compare routes and vehicle types from San Francisco Airport car rental. Those coming through Los Angeles may start from Los Angeles LAX car rental or a brand specific desk such as Hertz car rental at LAX. The best choice is the one that gives you a comfortable, stable vehicle for long distances, plus clear guidance on chains.
Practical checks at pick up:
Confirm tyre tread looks healthy and tyres are matching on the same axle. Test headlights, wipers, and heater. Make sure the screen wash is topped up and rated for cold. Learn how to switch on traction control and where the tow hook and jack points are. Take photos of wheels and lower panels in good light so you have a record before driving into slush.
Step 2, Know chain control in plain English
On routes to Mammoth, chain control is enforced by Caltrans and CHP. You will see signs such as “Chains Required” and staff may direct traffic into a chain installation area. Even if the road is open, speeds can be reduced and stopping distances increase.
California chain control commonly uses three levels:
R1: Chains required on all vehicles except passenger vehicles with snow tyres. Most hire cars do not have true snow tyres, so expect to chain up if posted.
R2: Chains required on all vehicles except 4WD or AWD with snow tyres on all four wheels. Most hire SUVs have all season tyres, so they may still need chains even if AWD.
R3: Chains required on all vehicles, no exceptions. This is rare and often means travel is extremely difficult. Many roads will close instead of remaining at R3 for long.
What to do when chain control is active:
Pull into the signed chain up area, do not stop in traffic lanes. Put hazards on. Fit chains on the correct driven wheels, usually the front wheels on front wheel drive, and rear wheels on rear wheel drive. Tighten, drive a short distance, then re tighten. Keep speed low, often 25 to 30 mph maximum, and avoid bare patches where chains can break. Remove chains as soon as you pass the “End chain control” signs, because driving on dry pavement damages chains and tyres.
Carry gloves and a kneeling pad. Snow is wet, grit is sharp, and you will not enjoy fitting chains with cold hands.
Step 3, Build a realistic US-395 winter plan
The classic approach from Southern California is to join US-395 northbound and follow it past Ridgecrest, Lone Pine, Big Pine, Bishop, then on to Mammoth Lakes. In good weather it is a scenic, easy drive. In winter, treat each segment as its own decision point.
Use this step by step plan:
1) Set your go, no go time. Aim to drive in daylight, especially if you are unfamiliar with mountain conditions. If heavy snow is forecast, consider delaying departure rather than pushing into worsening conditions late in the day.
2) Check conditions twice. Check the official road status early, then again just before you leave. Conditions can change within hours if a storm cell arrives. Also look for chain control announcements around Mammoth Mountain and the town, because local roads can be impacted even if US-395 remains open.
3) Expect slower speeds. If you plan using summer timings, you will feel rushed. Build in buffers for chain installation, plough convoys, and brief closures for clearing.
4) Decide your safe turnaround points. Bishop is a useful anchor because it has multiple fuel stations, food, and lodging. If conditions north of Bishop look poor, stopping there is often safer than pressing on.
Step 4, Fuel stops and range planning that actually works
Fuel planning is the quiet winter risk on US-395. Cold weather reduces efficiency, headwinds are common, and delays can mean long idle time with the heater running. Also, some smaller stations reduce hours in winter or sell out during busy ski weekends.
Use a simple rule: do not let the tank drop below half once you are north of Ridgecrest, and refuel again in Bishop if storms are likely.
Practical fuel checklist:
Fill up before you enter remote stretches. Ridgecrest and Lone Pine are common fill points. Big Pine and Bishop are reliable too.
Top up in Bishop. Bishop is your last major services hub before Mammoth. Even if the gauge reads two thirds, topping up here gives flexibility if chain control causes extended delays.
Do not assume Mammoth is easy. Mammoth Lakes has fuel, but prices can be higher and queues longer during peak arrival times. If a storm hits, you might prefer not to hunt for a pump in active snowfall.
Keep a small emergency margin. Aim to arrive with at least a quarter tank. That leaves room for driving to lodging, idling to defrost, or re routing if a closure forces you to wait.
Step 5, Pack a winter kit you can use in a hire car
You do not need expedition gear, but you do need the basics in case you sit still for a couple of hours. Keep these items accessible, not buried under luggage.
Recommended kit:
Chains that fit your exact tyre size and tensioners if required. Do not guess sizing.
Warm layers and waterproof gloves for fitting chains and handling cold metal.
Head torch in case you arrive at a chain up area after dark.
Ice scraper and a small brush for clearing lights and windows.
Water and snacks for delays. Think high calorie, non perishable food.
Phone charger and a backup battery pack.
Blanket and a simple first aid kit.
Windshield washer fluid suitable for freezing temperatures if the reservoir is low.
For car hire, avoid items that can damage the vehicle, like metal shovels used aggressively near bumpers. If you carry a shovel, choose a compact plastic one and use it carefully.
Step 6, Driving technique for snow, slush and black ice
Most winter incidents happen because drivers brake too late, accelerate too hard, or follow too closely. The aim is smooth inputs and lots of space.
Keep these habits:
Increase following distance. In snow, you may need five to ten seconds behind the vehicle ahead.
Brake early and gently. Let ABS work, but do not rely on it to shorten stopping distance on ice.
Avoid sudden steering. Gentle steering reduces the chance of losing grip.
Use lower speeds on descents. Engine braking helps keep control.
Be cautious on bridges and shaded corners. These freeze first and stay icy longer.
If you are fitting chains, drive as if you are protecting them. Sudden acceleration can snap links. If a chain breaks, stop as soon as it is safe, because a flailing chain can damage brake lines and bodywork.
Step 7, What to do if US-395 or local roads close
Closures can be short for ploughing, or longer during intense storms. Your priorities are safety, warmth, and accurate information.
When you encounter a closure:
Do not queue in an unsafe spot. If traffic is stopped on an incline, keep extra space in case vehicles slide.
Follow directions from CHP and Caltrans. They may instruct you to turn around, wait at a specific area, or exit to a safer location.
Choose a safe waiting location. Bishop is often the most practical place to pause, refuel, and reassess. Trying to wait on the shoulder in a blizzard is risky and may block emergency operations.
Conserve fuel sensibly. If you are stationary for a long time, run the engine intermittently for heat. Ensure the exhaust pipe is clear of snow to reduce carbon monoxide risk, and crack a window slightly for ventilation.
Update your accommodation and travel plan. If you are delayed, adjust expectations rather than rushing. Many winter problems happen late in the day when drivers try to make up time.
If you are flying in and building the trip around a wider California itinerary, consider planning a flexible pick up hub that suits your start point. Options such as Thrifty car hire at Sacramento SMF can make sense for travellers approaching the eastern Sierra from the north, depending on where you are staying first.
Step 8, Final pre departure checklist for Mammoth Lakes
Use this quick run through right before you leave your starting city or hotel:
Check road conditions and chain controls. Check weather for Bishop and Mammoth Lakes, not just your departure point. Confirm you have chains, gloves, and a head torch within reach. Fill the tank and buy water and snacks. Enter your destination and an alternative stop, like Bishop, into your navigation. Tell someone your route and ETA. If you are starting from Los Angeles and comparing collection points for car hire, keep your paperwork handy and review the support details from car hire at California LAX so you are not searching for documents in freezing wind.
With these steps, the Mammoth drive becomes a managed winter trip rather than a gamble. You cannot control storms, but you can control preparation, timing, and how you respond to chain control and closures.
FAQ
Do I always need chains to drive to Mammoth Lakes in winter? No, but you should expect chain control at some point during storms. Even AWD vehicles can be required to carry and fit chains depending on posted R1 to R3 conditions.
Can I use chains on a hired car in California? Sometimes, but it depends on the hire agreement and vehicle. Check the terms before you leave, and ensure you buy or rent chains that match your tyre size and wheel clearance.
Where should I stop for fuel on US-395 in winter? Plan to fill up in larger towns such as Ridgecrest, Lone Pine, and especially Bishop. North of Bishop services can feel more limited during storms, so arrive in Mammoth with a healthy fuel buffer.
What is the safest response if the road closes while I am driving? Follow CHP and Caltrans directions and avoid waiting on the shoulder in severe weather. Turn back to a safe town with services if instructed, and be prepared for delays rather than trying to push on.
Is it better to drive to Mammoth during the day? Yes. Daylight improves visibility, helps you spot ice and snow drift, and makes chain fitting safer. Night driving also increases the impact of fatigue on a long mountain route.
