It's been called “the crown jewel of West Texas” and “the heart of the Franklin Mountains.” Castner Range is 7,000 acres of cliffs, canyons and open desert – in the center of El Paso.

The range is famous for its Mexican poppies. When conditions are right, the radiant blooms create a spring display like nothing else in Texas.

El Pasoans have been pushing for preservation of this undeveloped land for decades. Now, conservationists hope President Obama will answer their long effort – and proclaim Castner Range a national monument.

The Franklin Mountains rise above El Paso in cliffs of red and orange. In 1979, the state acquired much of the range. At 24,000 acres, Franklin M...