Willamette Valley ecoregion
... that the historic floodplains of Oregon's Willamette Valley ecoregion rarely function today, due to dams in the Upper Willamette Basin?
... that the historic <a href="./Floodplain" id="mwBNw" rel="mw:WikiLink" title="Floodplain">floodplains</a> of <a href="./Oregon" id="mwBN0" rel="mw:WikiLink" title="Oregon">Oregon</a>'s <b id="mwBN4"><a href="./Willamette_Valley_(ecoregion)" id="mwBN8" rel="mw:WikiLink" title="Willamette Valley (ecoregion)">Willamette Valley ecoregion</a></b> rarely function today, due to <a href="./Dam" id="mwBOA" rel="mw:WikiLink" title="Dam">dams</a> in the Upper Willamette Basin?