Take a look outside on any given summer day, and you'll likely see the same thing around your neighborhood -- empty streets with no kids.
The fact is kids are spending less time outdoors. Even visits to national parks are down.
"We've seen a decrease overall in park visitation and that's been across the country," said Yosemite National Park ranger Tom Medema.
Yosemite National Park ranger Tom Medema is among those who have watched technology eat away at the number of kids who are actually experiencing nature.
"More and more kids are on their cell phones, they are on their iPods, they are on their video games and their computers and so, getting disconnected from those things feels uncomfortable for people," Medema.
"The problem is there are all kinds of new barriers between children and nature," said "Last Child in the Woods" author Richard Louv.
Louv is Chairman of the Children and Nature Network and the author of "Last Child in the Woods," an in-depth look at how children have become detached from nature. Louv calls the phenomenon "nature deficit disorder."
"Just in general, the psychological health, the physical health, even the spiritual health is really connected to our experience with nature and we're taking that away from kids," said Louv.
Research supports his claim. A recent University of California study shows that while 90 percent of 9-year-olds get a few hours of exercise outdoors most days and fewer than three percent of 15-year-olds do. Hearing that, it probably comes as no surprise that 20 percent of American children are currently considered obese.
Louv believes the problem can be reversed if parent's just got their kids outside more.
Louv's book came out two years ago, and has inspired many parents to get their kids out of their houses.
Former school administrator Mary Roscoe's kids are all grown up. But she helped start the "Children in Nature Collaborative" in Mountain View after hearing Louv speak.
"We'll start to see children playing in their yards again," said Roscoe.
Her group is working with local governments and community groups to get kids out of the house.
"What we are thinking here is a series of play days, some would be in nature centers, but some could be in neighborhoods where you could block off neighborhoods, and just create play," said Roscoe.
Mike Lanza wants everyday to be a "play day" in his neighborhood. He started "Playborhood," an online community designed to get kids back onto the streets to play.
"We want kids playing outside every day. We want kids that when they think about what am I going to do today, we want them very high on their list to say 'well if I just go outside, something will be going on,'" said Lanza.
Scott Vanderlip of Los Altos Hills has no problem getting kids into his yard. He wants his daughters to get out of the house and climb trees.
"You got to push them outside, a lot of times they won't do it by themselves," said Vanderlip.
Vanderlip turned his backyard into an outdoor community theater of sorts. The play is actually a ploy to get neighborhood kids to spend more time out of their houses.
"From four to five, the kids just come over and play and swim, and jump on the trampoline, and have a good time together, than from five to six we practice," said Scott Vanderlip from Los Altos Hills.
Louv says most kids don't need to be tricked into enjoying the outdoors -- just nudged.
The junior ranger program is the nudge that park rangers in Yosemite say has been reeling them in since the 1930's.
"A lot of people have heard about nature deficit disorder and about kids being disconnected from the outside, and being plugged in all the time, so we have a renewed focus now on junior ranger programs," said Medema.
Thanks to that renewed interest, they've gone from one junior ranger program a day to three. The kids in the program don't seem to notice that the TV's, iPod's, and cell phones are nowhere in sight.
"I am learning a lot about bears, squirrels, deer," said one girl.
"It's pretty cool, we're learning a lot about the environment," said one boy.
Louv says you don't have to go to extremes, or even travel, just open the front door.
"The great thing about this is that you don't have to wait for funding - you don't have to wait for somebody else's permission, you just do it," said Louv.
Even Congress is pushing a bill to fund more outdoor education. The "No Child Left Inside Act" is currently making its way to the president's desk.
Written and produced by Ken Miguel.