Leading attractions in Arkansas are the mineral waters and recreational facilities at Hot Springs, Eureka Springs, Mammoth Spring, and Heber Springs. The Crater of Diamonds, near Murfreesboro, is the only known public source of natural diamonds in North America. For a fee, visitors may hunt for diamonds and keep any they find; more than 100,000 diamonds have been found in the area since 1906, of which the two largest are the 40.42-carat Uncle Sam and the 34.25-carat Star of Murfreesboro. The World's Championship Duck Calling Contest is held at the beginning of the winter duck season in Stuttgart.
In support of the industry, the Arkansas Tourism Development Act of 1999 provides incentives for qualified new or expanding tourism facilities and attractions. The program applies to cultural or historical sites; recreational or entertainment facilities; natural, theme, and amusement parks; plays and musicals; and gardens. To qualify, the project must cost more than $500,000 and have a positive effect on the state. The state has 14 tourist information centers. In 2002, the state had about 19.9 million visitors with travel expenditures reaching over $3.9 billion dollars (a 2.8% increase from 2000).