When it starts to look like this in Yosemite...

This is the view from Sentinel Dome above Yosemite Valley this week. Half Dome is always the landmark you want in the middle of these shots. Everybody knows what it looks like.

But not everybody understands how important it is to see the dome covered with snow. It's an indicator of the Sierra snowpack. If you don't see snow up there most of the winter, you've got a water problem.

And if you followed the webcam that takes these photos, you know we have a problem. Most of November, December and January, there was no snow up there. The snowpack stands at about a quarter of the April 1 average.

The state had a monster year last winter, so it's not a statewide emergency yet. The reservoirs are still fairly full. That's why people aren't making a scene about this yet. But they will worry next fall. A second dry year will make life very difficult for farmers, cities, industries and hydroelectric power producers.

One more time: Look out across the rooftop of California in the background of this photo. That's where your water comes from. More than half of the state's water supply melts slowly and thunders through these granite canyons down to 37 million people.

No place like this on Earth in deep winter

When I saw this photo a few years ago, I remembered scenes in Yosemite Valley like this from the 1990s when I started covering Yosemite National Park as a beat for The Fresno Bee. It's the best place on Earth in deep winter. This photo tells you why.

The photographer, Kenny Karst, works for park concession, but not as a photographer. He was head of the public relations department when he took this shot. I think his photo work is really nice.

Anyway, Yosemite Valley is fascinating in winter. There are very few tourists in the valley when it snows like this. Sometimes the temperature drops into the teens after a big storm, and it really is a slice of icy heaven.

Surrounded by the ancient, granite cliffs, you can sense what it was like when this valley was filled with ice during glacial times. The largest glacier in the Sierra was in the next watershed north of Yosemite Valley. It's called Hetch Hetchy Valley on the Tuolumne River.

We'll talk a little more about the dam and the reservoir stashed in Hetch Hetchy.

Might not need to worry about snow patches this August

Last August, there was still snow all over the place in the high Sierra. This photo was in the Southern Sierra, just east of the crest.

Trust me, unless the winter gets rolling a little bit soon, this snow patch will not be around.

The hiker's name is Tim Crosse, a 20-something guy who likes seeing nature up close. By the time we were finished with this backpack, he knew what a Sierra glacier looked like. He had listened to the gentle drip at night as the snow and ice melted. He drank ice-cold water from a glacial tarn.

He's one of those youngsters who likes to check things out before he makes decisions -- like casting a vote. I won't get into the connection between water and California voting. That's a subject for a different blog.

Back to the high Sierra, I think it's really important to show the next generation what's up here and connect the dots. I know plenty of people, young and old, whose world is inside four walls. That was true for me when I was 20 years old.

I'll have a few more blogs soon about seeing California up close. And you don't have to put your phone on vibrate. I'm hoping to get you into places where there is no cell coverage.

Southern Sierra may hold a climate key

I'm heading again into the glacier belt in the Sierra Nevada to get a closer look at where California's water starts.

I'm not saying exactly where I'm going yet, but you will definitely recognize it a lot easier than the photograph I've loaded with this blog item. The photo was taken in August at Dusy Basin in Kings Canyon National Park.

The glacial wilderness above 10,000 feet in the Sierra is often quite arid during the warmer months. But the Southern Sierra is the highest part of the mountain range. The snow tends to stick around all season long on many years, no matter what's going on elsewhere.

What does that mean for California as the planet warms?

I asked a fishery biologist who has had a lot of influence around the Sacramento-San Joaquin River Delta. Peter Moyle told me these wind-blown plateaus and peaks may be the last place where a decent snowpack remains in the future.

And that means what to the state? Remember, there are two rivers flowing to the delta. The vastly more important Sacramento River carries a lot more water, while the San Joaquin is considered a kind of murky mess.

But a restored San Joaquin with real snowpack 70 years from now might become a more important piece for conservation.

More later. And, by the way, I've decided not to take experts with me this year. Instead, I'm going with a fresh-faced young man who represents our future. Again, stay tuned.

A friendly yellow-bellied marmot

I had to sweet talk this yellow-bellied marmot for 20 minutes to come out from under a rock at 11,500 feet in August. I think he (or maybe she) thought I was going to toss out some food. No such luck for the critter.

Bugs were eating me alive as I shot this photo. Didn't seem to bother the marmot.

There were marmots, pikas and other small mammals all over the place. It looked like spring up there in late August. This was Dusy Basin in Kings Canyon National Park.

At night, there was not a breath of wind. It was a toasty 55 degrees. Loved the sound of dripping glaciers at night. And the daytime sights were equally amazing.

Next year's trek -- wanna go?

A few ideas about the next trek to the top of the watershed:

* I'm not driving 250 miles next time. I want to backpack out of Florence or Edison lake in the San Joaquin River watershed.

* Buy the bug-proof clothing and a ton of bug spray. I will not go to sleep in my tent again staring at splotches of my own blood coming out of smashed mosquitoes.

* Get a scientist to go with me. Maybe a hydrologist. Maybe a geologist or a biologist. Might be a little more crowded. But it would make good conversation. And what about asking other journalists to join us? A few issues-oriented discussions over a campfire?

* Take another 20-something along. Mark Crosse and his son, Tim, came along and it was wonderful hearing Tim's thoughts. He's also amazing at quoting the funny lines in the film "Ghostbusters."

* The elevation-reading device from L.L. Bean does not work. It measured at least 400 feet lower than we actually were most of the time. But the temperature, time and barometer stuff was pretty helpful.

* Nothing else. Other than the bugs and the cheap elevation gadget, I had the right gear and the right distance at the right elevations. Too bad spring was just popping out at 11,500 feet in August.

Sierra trek: reaction to reactions

Just a note after having a few conversations about the post on the high Sierra trek.

* For the folks who dearly love extreme sports in the Sierra, more power to you. I mean no offense by pointing out that many people would consider your passions to be slightly crazy. Your passions indeed are slightly crazy.

* For naturalists who appreciate all facets of the Sierra, including swarms of blood-thirsty mosquitoes, I see where you're coming from. I just don't want to be sitting anywhere near you when you're appreciating those maddening bugs.

* For the people who don't see why I fuss so much about the Sierra and its importance to California, I get it. And it's fine by me. But you breathe air. You turn on the tap, and the water comes out. Do we need the Sierra for those basic things? Yeah. If you live in California, you pretty much need that hulking mountain range.

* For you government wonks in various agencies dealing with the Sierra, thanks for your views on technical details. In your travels and work in the Sierra, I urge you to be as passionate as any one of the people I mentioned above.