<P> The idea that the dunes could be destroyed by gold mining or concrete manufacturing alarmed residents of Alamosa and Monte Vista . By the 1920s , the dunes had become a source of pride for local people , and a potential source of tourist dollars for local businesses . Members of the P.E.O. Sisterhood sponsored a bill to Congress asking for national monument status for Great Sand Dunes . Widely supported by local people , the bill was signed into law in 1932 by President Herbert Hoover . Similar support in the late 1990s resulted in the monument 's expansion into a national park and preserve in 2000 - 2004 . </P>
<P> The idea that the dunes could be destroyed by gold mining or concrete manufacturing alarmed residents of Alamosa and Monte Vista . By the 1920s , the dunes had become a source of pride for local people , and a potential source of tourist dollars for local businesses . Members of the P.E.O. Sisterhood sponsored a bill to Congress asking for national monument status for Great Sand Dunes . Widely supported by local people , the bill was signed into law in 1932 by President Herbert Hoover . Similar support in the late 1990s resulted in the monument 's expansion into a national park and preserve in 2000 - 2004 . </P>
when did the great sand dunes become a national park
when did the great sand dunes become a national park
2000 - 2004
2000 - 2004