When you think of them, what might come to mind are these supermassive chunks of immovable ice, but some of them are anything but Jim Glacier, the smallest one in Montana's Glacier National Park, covers only about five acres, which is like five football fields.

And the Alaska Almanac states that the state of Alaska alone is home to 100,000 glaciers.

Also, they move maybe not so fast that you can watch them drift like a boat over water.

But whether glaciers are crunching downward through valleys are spreading away from a central point.

These ice masses slip, slide, creep and crawl across the surface, scientists say.

Most of the world's glaciers are shrinking, those some are getting larger and investigations were taking place worldwide.

CNN's Holly Firfer recently took a tour of one that's said to be the largest U.

S glacier that's accessible by a car.

Glaciers majestic and mysterious.

These icy giants make up about 10% of the world's landmass remnants of the last ice age, and they continue to transform as new layers of snow berry and compressed the layers before it here in Alaska, about 100 miles north of Anchorage, sits the Matanuska Glacier.

It's about 27 miles long, four miles wide.

So we thought, Hey, why not hike it first, we needed a guide in the winter.

Especially.

Glaciers can be dangerous because you can't see below the snow everything on the trail safe.

You take one step off the trail and there might be a hole there, so it is really important that we do stay on the trail.

So we joined guides Tiffany and John from Salmon Berry Tours for our Glacier Hike adventure.

We drive right up to the edge of it, and then we put on gear way.

Have spikes for our feet.

We put on helmets for precaution.

After a brief introduction to the glacier, we were off.

Now we got some moose tracks right over here.

This'll way get up to use, um, hires where there's some terrific views of the surrounding valley.

Andi, All the while, we're looking around at the features of the glacier.

Um, there's black ice basil ice.

Uh, there's Mullan's and crevasses.

If you are wondering what those are, so were we, but not for long.

Part of our adventure was the hike.

The other part was learning about these massive natural wonders.

Ah, crevasses.

A crack in the ice, various sizes.

Some are small and some can swallow a vehicle.

So Mulan's air holes in the ice they form when flowing water flows off of it on, it's sort of rose into the glacier itself.

It creates some really amazing features, just kind of weird sort of carvings inside the ice, a giant hole in the ice.

Okay, then let's check it out.

So we're gonna go in here about two at a time.

You don't have to be perfectly physically fit way.

Always like to know if you have any limitations physically before you come out.

It's nothing extreme in terms of going up or down inclines.

But just be prepared for stepping on uneven surfaces.

We're only about a mile in, and the views are becoming even more spectacular every step you take.

Perhaps what's most remarkable, besides the dramatic landscapes, is the vastness and the stillness of the surroundings.

A lot of times, when I take groups out there, I'll get to a point on the tour and I'll say, Okay, let's just stop and let's just take a couple minutes and listen to the silence and it without fail after, like a minute.

You just You just kind of start looking around like you feel that, can't you people that come out they might be a little intimidated by the cold or by the drive.

You know, we take care of a lot of that, and so we tryto make it so that it's, um, something that you can really.

You can really take memories back.

It's not something people do every day, right?

Say that you walked on a glacier.

Its's really unique.