monoxide - an oxide containing just one atom of oxygen in the molecule

metal, metallic element - any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.

cobalt 60 - a radioactive isotope of cobalt with mass number 60; a source of exceptionally intense gamma rays; used in radiation therapy

cobaltite - a rare silvery-white mineral; important ore of cobalt

smaltite - a gray mineral consisting of cobalt arsenide and nickel; an important source of cobalt and nickel

dissenter, dissident, objector, protester, contestant - a person who dissents from some established policy

Mesa Verde National Park - a national park in Colorado containing prehistoric cliff dwellings; semiarid landscape

Rocky Mountain National Park - a national park in Colorado having mountains and lakes and streams and forests

American state - one of the 50 states of the United States

U.S.A., United States, United States of America, US, USA, America, U.S. - North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776

Boulder - a town in north central Colorado; Rocky Mountains resort center and university town

Colorado Springs - a city in east central Colorado on the eatern edge of the Rocky Mountains; popular tourist center and site of the United States Air Force Academy

capital of Colorado, Denver, Mile-High City - the state capital and largest city of Colorado; located in central Colorado on the South Platte river

Pueblo - a city in Colorado south of Colorado Springs

Arkansas River, Arkansas - a river that rises in the Rocky Mountains in Colorado and flows southeast through Kansas and Oklahoma and through Arkansas to become a tributary of the Mississippi River

Colorado River, Colorado - a river in southwestern United States; rises in the Rocky Mountains of northern Colorado and flows southwest through Utah into Arizona (where it flows through the Grand Canyon) and then southward forming the border between California and Arizona and finally into Mexico where it empties into the Gulf of California; an important source of water in the southwestern United States

Colorado Plateau - a large plateau south and west of the Rocky Mountains; abuts mountains on the north and east and ends in an escarpment overlooking lowlands to the south and west; the Grand Canyon is carved out of the southwestern corner

North Platte, North Platte River - a river that rises in northern Colorado and flows northward into Wyoming and then eastward and southeastward through Nebraska where it joins the South Platte to form the Platte River

Pike's Peak - a mountain peak in the Rockies in central Colorado (14,109 feet high)

Republican River, Republican - a tributary of the Kansas River that flows from eastern Colorado eastward through Nebraska and Kansas

San Juan Mountains - a mountain range in southwestern Colorado that is part of the Rocky Mountains

Mount Sherman, Sherman - a peak in the Rocky Mountains in central Colorado (14,036 feet high)

South Platte, South Platte River - a tributary of the Platte River