Driving and Camping Above 8,000 Feet

The Eastern Sierra makes it very easy to gain elevation fast. You can have breakfast in Bishop at 4,100 feet and be parked above 10,000 by mid-morning without doing anything that feels dramatic. The vehicle notices, and so do the people in it.

What happens to the engine

A naturally aspirated engine loses roughly three per cent of its power per thousand feet. It is a straightforward consequence of thinner air: less oxygen per intake stroke, less fuel burned, less power made.

At 10,000 feet that is about a third of your power gone. On a grade, towing, in low range, on a hot afternoon, that is not a subtle difference. Things that were easy at valley elevation want a lower gear and more patience.

Forced induction is the real fix. A turbocharged or supercharged engine compresses its own intake air and loses far less to elevation — which is why a diesel with a turbo on it feels so much less bothered by a high climb than a naturally aspirated petrol V6 does.

Nothing about this is a problem. It is just a number to plan around: expect less power, expect to run lower gears, and do not be surprised when a climb that felt fine last month at 4,000 feet feels like work at 9,000.

What happens to cooling

Thin air cools less effectively, and long low-range climbs are the hardest work a cooling system ever does — high load, low road speed, not much air moving through the radiator.

Any weakness in the system shows up here rather than on the highway. A marginal fan clutch, a tired radiator, a slightly low coolant level, a radiator packed with dust off a washboard road — all of it is survivable at valley elevation and all of it turns into a temperature gauge climbing on a long grade.

Watch the gauge on sustained climbs. If it starts moving, back off and let it recover before it becomes an event. Turning the cabin heater on full genuinely helps, unpleasant as it is in August.

What happens to cooking

Water boils at about 194°F at 10,000 feet instead of 212°F at sea level. Lower boiling temperature means everything boiled takes longer to actually cook, and longer cooking means more fuel.

Carry more gas than the arithmetic suggests. Pressure cookers are the real answer if you cook properly at elevation, and if you are just boiling water for coffee and dehydrated food, you will barely notice.

What happens to people

This is the part worth taking seriously, because it is the part that ends trips.

The pattern that makes people ill is gaining a lot of elevation and then sleeping at the top of it. Driving high for the day and coming down to sleep is far easier on everyone. The common guidance above 8,000 feet is to avoid raising your sleeping elevation more than about 1,600 feet a night.

Early symptoms are a headache, poor sleep, no appetite and a general flatness. That is ordinary and usually passes with a night, water and an easy day. What is not ordinary is getting worse instead of better, breathlessness at rest, or confusion and loss of coordination — those mean go down, immediately and at night if necessary. Descent is the treatment and it works fast.

Everything else is straightforward: drink more water than you want to, go easy the first day, and do not treat the first night high as the night to have a few drinks.

On this corridor the practical version is simple. Camp in the Owens Valley or on the lower stretches of the road, drive up to the high country in the morning, and come back down to sleep.

Weather

High country weather arrives faster and harder. In late summer the monsoon pushes moisture up from the south and thunderstorms build over the crest through the afternoon — often from a clear morning, often quickly.

Above treeline in the Whites there is nowhere to shelter and nothing higher than you are. Be off the exposed ground by early afternoon in thunderstorm season, and treat a building cell as a reason to leave rather than a reason to get the camera out.

Wind is the other constant. Ridge camps look spectacular and get punished. Tuck in behind something, put the awning away before bed, and expect it to blow all night anyway.