How do you know when a lake is safe to cross?

[Love the Sierra]

Hi everyone,
I am starting a new topic since winter is lasting a long time this year and other intermediates like me may be wondering the same.
I have taken Ned Tibitts’ courses, read tons from NOLS books, but no one seems to cover when it is safe to cross a lake. In other words, how can you be absolutely sure that it is frozen solid enough to make a safe crossing?
Thanks so much to all of you experienced folks.
Aura

[Wandering Daisy]

I wound never cross a lake during spring, particularly on foot. I have walked on the near shore ice if easier than up on the trail. Mid-winter January may be different and on skis.

[maverick]

HST member, and former backcountry ranger, John Dittli is the ice skating specialist on Sierra lakes. I will contact him to chime in with some pointers.

[texan]

That's a tough decision. I used to ice fish all the time at Sabrina and South Lake the first couple weeks of the opener but no later than Mid-May. Infact, the latest I iced fished South Lake was in 81 when I was 17 and we left on May9th. That year was a big snow year. We had to walk from Parchers because the road wasn't plowed and we camped where the restrooms are now where the TH starts. There was a lot of snow on the ground and the ice was 2 feet thick at least. There was people ice fishing too so I felt comfortable. I would never go out on the ice unless I saw people out there too. Now I am 58 and there's no way I would be out on the ice any lake past Mid-May. But I am ice fishing, if I was just trying get by the lake, I would just walk around, especially in the backcountry, there's no help if you fall in. Safety first.

Texan

[texan]

Correction it was 81-82 winter and we went to South Lake May7,1982, and came out May9,1982 just looked at some old pics. 81-82 was a big year and little less than 82-83.

Texan

[Love the Sierra]

Daisy and Texan, thank you! I always thought that I was super wimp/chicken because I never crossed those tempting lakes, no matter how inviting.
I skied three times across frozen lakes in the Mammoth Basin. I was with a backcountry ski instructor who had been skiing for decades and I trusted her. It was so DELIGHTFUL, Skiing the smooth surface was so much fun!!

Once, coming down from Virginia Lakes, the wind was SO STRONG, we were able to spread our arms like sails and “wind ski” It was awesome fun!! I believe that was a spring trip in a low snow year since that was the only skiable snow around. (the reason we were coming down fast. I was literally blown off of my feet traversing a ridge! If the instructor had not been there, I would never have been able to get up again. …Then of course, if the instructor had not been there, I would have never skied something like that in those conditions. )

But I digress..l Now that I will have a heavy pack, short cutting across a lake would be great and seems like it could be safer than a ridge above the lake. That is why I asked.
Maverick, I am eager to hear what John Ditti says
Thank you all!

[c9h13no3]

Ice is weakest near the outlet to the lake, so I never ski over that. I also only ski across lakes with a lot of snow on top, preferably with tracks from other “testers” before you.

John Dittli has some cool videos backcountry ice skating. But he carries ice screws to measure ice thickness and some spikes to help self rescue if you fall in.

[paul]

I have skied across a lot of lakes in the Sierra, and the simple rule is; stay away from the blue. Where the surface is white you have snow on top of ice (this year it might be ten feet or more of snow!), and you will have no problems. If you see blue, the ice/snow is wet, and may be thin. If you see actual ice, stay off of that. At any time other than the early winter when the lakes freeze before getting snowed on, any ice you see is from a recent refreeze, so it is almost certainly thin and unsafe.

[Gogd]

I come from the upper Midwest. The rule of thumb, there, is stay off lake ice that has not been inspected for safety. In fact it is against the law in many counties to cross uninspected ice. Snow covering ice is no assurance it is safe. Snow acts as an insulator. If the water is warm, relative to the average air temperature - this happens whenever the air temperature is below 32 degrees - the snow will facilitate the ice getting warmed from below. I am no ice expert. Thus I just avoid this risk altogether.

Do people flout such caution? Yes.

Do they get away with it? Usually.

Do people fall in and drown? Yes

I must admit those ice skating tubes under the Minarets, and lakes proximal to Mt Darwin are absolutely mesmerizing.

Ed

[jôhorn]

It's cool when your GPS track makes you look like Jesus.