The statement that is true about the Cascade Mountains Region is It is the state’s most mountainous region, because the Cascade Mountains region is the major mountain range of the west of North america, because it's extended from the south of British Columbia, passing over Washington and Oregon and reaching to the north of California. Also, in that mountain range are located several volcanoes (called High Cascades) and simple mountains (called North Cascades). Moreover, the Cascade Mountains are part of the Paciffic Oceans's Ring of Fire, and all the volcanic eruptions occurred since the last 200 years in the U.S, have been generated in the Cascade Mountains region.