WASHINGTON - Get ready for another decade of quarter-mania. The U.S. Mint is hoping to repeat the phenomenal success it had with the 50-state quarter program with a new series of designs featuring the country's national parks and forests.

The first five designs were unveiled in a ceremony Wednesday at the Newseum with the first coin scheduled to go into circulation next month. It will feature Hot Springs National Park in Arkansas.

If the new program attracts the interest of the original state quarters program, which began in 1999, it will be a true blockbuster. That one got 147 million people - nearly half the country - to participate in collecting those coins, according to Mint surveys.

"We think we are generating a lot of excitement with the new program," Mint Director Ed Moy said in an interview.

The new program will have 56 quarters in all, one for each state and territory and the District of Columbia, with five new designs introduced each year. The program will end in 2021 with a quarter honoring the Tuskeegee Airmen National Historic Site in Alabama, which was created by Congress in 1998.

"Today, we celebrate the breathtaking landscapes and natural heritage of America the Beautiful by commemorating our country's most treasured places on our currency," Interior Secretary Ken Salazar said at the unveiling ceremony.

The sites, nominated by each state, are being placed on the coins in the order that Congress put them under the care of the federal government, starting with Hot Springs in 1832, more than eight decades before the National Park Service was created.

This year's coins will honor the country's four oldest national parks - Hot Springs, Yellowstone, Yosemite and the Grand Canyon - as well as Mount Hood National Forest in Oregon.

Congress authorized production of the new quarter series in 2008. The states' selections were reviewed by the Mint's artists and engravers to make sure that images featuring each of the sites could be depicted successfully on a coin. The final choices were approved by Treasury Secretary Timothy Geithner.

The Yellowstone coin features the Old Faithful geyser with a bison in the foreground while Yosemite depicts El Capitan. Each coin has the name of the park and state being honored and the words "E Pluribus Unum" on one side along with the year the coin is being issued.

Just as with the 50-state quarters program, the "heads" side of the coin will continue to feature a profile of George Washington.

One challenge to collecting this time around could be the weak economy. The Mint produces to meet demand, with fewer coins needed in years when economic activity is slower.

Moy said the 50-state quarter program started off slowly and then built up demand as more people learned about the coins and started collecting them. At the peak of that program, he said that as many as 650 million quarters for each design were being minted.

But now, with the economy still struggling to emerge from a deep recession, the number of quarters scheduled for each of the initial issues of the new series is down to less than one-tenth of that amount.

"The economy has stabilized but the recovery is lagging a bit so there are not as many quarters being demanded by banks right now," Moy said. "But we think that once people know about this program, they will start checking their change looking for the new coins."