Today’s Wonder of the Day was inspired by EMMY from , . EMMY Wonders, “How long would it take to walk across the United States” Thanks for WONDERing with us, EMMY!

What's your favorite way to exercise? Some kids love to play sports. Others might like to run or ride a bike. Still others prefer simply to go for a stroll around the neighborhood.

If you like to walk, you probably also enjoy hiking. Those who really love to hike might one day take on a big challenge, such as completing the Appalachian Trail or the Pacific Crest Trail. A few brave souls might try something even more daring: walking all the way across the country!

How long would it take to walk across the United States? Flying from New York to Los Angeles can take several hours and airplanes travel several hundred miles per hour. Walking rather than flying across the country must take a lot longer. But is such a trip measured in days, weeks, months, or even years?

If you give it some thought, you'll soon realize that answering the question of how long it takes to walk across America isn't exactly straightforward. There are all sorts of factors that affect how long such a trip would take.

For starters, what route would you take? You could go from Boston to Seattle, New York to Los Angeles, or even San Diego to Miami. Walking across America merely means starting on one coast and walking to the other. The route you choose can have a dramatic impact upon the number of miles you have to walk.

To further complicate things, you can't just walk in a straight line from point A to point B. If you tried, you'd find yourself trespassing on private property, swimming across lakes and rivers, and climbing up and down mountains.

So do you want to stick to walking along interstate highways, which can be dangerous, or would you rather walk on trails? Thanks to the American Discovery Trail, the nation's first coast-to-coast, non-motorized trail, you can get from one coast to the other without relying upon heavily-traveled highways.

The American Discovery Trail stretches from Delaware to California, with alternate northern and southern routes through the middle of the country. All told, the trail covers over 6,800 miles. For our purposes, however, we'll average the mileage of most of the routes across the country, which gives us an average trip of approximately 3,000 miles.

There are many factors that can affect how quickly you can cover those 3,000 miles. How quickly do you walk? How many miles can you average per day? Will you walk every day? Or will you take breaks? What about tough terrain in the mountains and the desert? What about bad weather?

What will you eat and drink? Where will you sleep? Can you carry all the gear you need on your back or do you need to push a rolling cart? These are just a few of the many factors that will influence how long it'll take you to walk across America.

A couple dozen people have completed a cross-country trek on foot. Based upon their journeys, you can expect it to take about six months to complete such a trip if you're well-prepared. Of course, it can take much, much longer or, if you're an exceptional walker and planner, you might make it in less than six months!

Wonder What's Next?

Tomorrow’s Wonder of the Day might stir up a lot of emotions!