Millions of tourists travel to Alaska every year to marvel at its wildlife, national parks and its glaciers. But, most of those glaciers are shrinking fast.

Dozens of helicopters make the trip every day, bringing tourists to glaciers in Alaska. Trekkers navigate around crevices and streams and even drink from them.

Scientists say these days, there are more areas with water flow because glaciers all over the state are melting at a decidedly un-glacial rate—something that began several decades ago.

Shad O'Neel is a glaciologist at the Alaska Science Center.

"Conclusively the data shows the climate is warming in Alaska," O’Neel says.

The National Park Service says there are 100,000 glaciers in Alaska and that 95 percent of them are getting smaller or have stopped advancing.

Glacier Bay National Park in Alaska was established in part to study the cycles of glaciers. The park's showpiece glacier, Margerie, had a noticeable loss of ice in just the past year.

The changing landscape is even more obvious when you compare Columbia glacier on the state's south coast.

The image on top was taken last month, and the one on the bottom, 13 years ago when no water was visible.

"The reason that we've been losing so much glacier ice is, in part, due to warmer summers. It's also due, in part, to a shorter winter."

For those experiencing a glacier for the first time, like Julie and Robert Broaddus from Tulsa, the changes are concerning.

"It makes me think about my brand new grandbabies, who are twins, 3-months-old,” Julie says. “Will they be able to take a trip like this when they're my age?"

More than half of the ice that makes up Alaska's glaciers is expected to be gone by the end of the century.

Scientists in Alaska have measured and studied two glaciers for the past 50 years. They also monitor the state's glaciers by air. That data gives them a more complete picture of what's happening.

Copyright 2017 CBS News.