(Inside Science) -- The National Park Service is offering free entrance for nine days this month, from April 16 to 24, in honor of National Park Week 2016. While there's no replacement for exploring our national parks in person, sometimes duty calls.
So, for those of us stuck in the office instead of frolicking in nature next week, we've compiled a few ways to explore some of the country's national parks, monuments and historic sites remotely.
Located in a cove near Anacapa Island, one of the five islands that make up Channel Islands National Park off the coast of Southern California, this live underwater cam offers glimpses of the kelp forest and some of the many species that call it home. Warning: the kelp waving in the current can be a bit hypnotic.Every summer, hundreds of thousands of sockeye salmon course up the Brooks River in Katmai National Park and Preserve in southern Alaska on their way to spawning sites. When they reach Brooks Falls (depicted above), as many as 200,000 to 400,000 may successfully make the jump. But not all the fish get past the bears, and this cam provides views of the action. While the cam won't be live again until the summer, you can still watch highlights from previous seasons.
A number of other parks offer eHikes, which you find on their websites. In Grand Teton National Park in Wyoming, you can hike around String Lake, explore the Moose-Wilson corridor, or even eClimb to the summit of Grand Teton. Want to explore the high ground but afraid of heights? Check out this Angels Landing eHike in Zion National Park in Utah. Tired of eWalking? You can eCruise in Acadia National Park in Maine.Well, eHike, that is. Glacier National Park's website offers two eHikes -- one explores the popular Trail of the Cedars and the Avalanche Lake day hikes while another offers views and sounds of the Dawson-Pitamakan passes in Two Medicine, one of the park's most popular backpacking routes.
Using its Trekker backpack cameras, Google has created other virtual hikes and climbs. You can scale El Capitan in Yosemite, paddle down the Colorado River, and explore the Grand Canyon. Other sites with the 360-degree panoramas include California's Joshua Tree and Sequoia national parks among others.
In 2012, the former home and workplace of Cesar Chavez near Keene, California was designated a National Monument. Now, a new virtual tour reveals the visitor center, memorial garden and glimpses of Chavez's office as it was from 1970 to 1988.Located in Hawaii, Puuhonua o Honaunau National Historical Park comprises former royal grounds and an area that was once a place of refuge for ancient Hawaiian fugitives, defeated warriors and civilians during times of fighting. This virtual tour takes you around the park, which is still considered a sacred site.
Like lichens and mosses? Explore them in all their splendor with this eTour of Denali National Park and Preserve in south-central Alaska. And get a sense of how the landscape of the park has changed over the years with this eTour of the park that compares historical and present-day photos.
The Park Service also offers a way to explore virtually other parks or themes such as air quality and paleontology through their interactive program, Views of the National Parks.
And check out these beautiful panoramas of Petrified Forest National Park in northeastern Arizona.
Fly-through of historic Carlsbad Caverns stairs, Credit: HABS, HAER and HALS
In 1925, the newly-established Carlsbad Caverns National Monument in southeastern New Mexico began constructing wooden staircases that allowed visitors to access the site's maze of deep limestone caves, replacing the previous method of entry -- being lowered down in buckets used to mine guano. By the 1950s, the monument had become a national park and started replacing its dirt paths and rickety staircases with winding, paved trails. Six abandoned and moldy flights of stairs that survived into the present have been slated for removal. But first, they were documented by the Heritage Documentation Programs of the Park Service in the above fly-through.
The same program has created several preliminary, animated fly-throughs of other historic sites including the main hospital buildings of Ellis Island, part of the Statue of Liberty National Monument, and the lighthouse of Cape Hatteras National Seashore in North Carolina.
Never heard a dawn chorus of coyotes and birds from the Hayden Valley in Yellowstone National Park? Or the otherworldly sound of ice freezing on Yellowstone Lake? A growing collection of animal sounds and other environmental recordings from the park and across the West is changing that. The audio files, as well as a new podcast series, are developed through a project between Montana State University Library's Acoustic Atlas and the park.
You can listen to the sounds of Denali National Park and Preserve here, part of the park's efforts to record its various soundscapes, including natural and human-made noises. Want to take the sounds with you? You can even download one of ten recordings as a ringtone for your phone.
The Park Service has its own sound gallery, too.
And don't miss these "soundscapes" of Mammoth Cave National Park in Kentucky -- although you'll need a few musician friends if you want to recreate them yourself.
These only whet your appetite for the great outdoors? Get out there yourself. This year marks the 100th anniversary of the Park Service, and a host of events are planned across the country.