Created in 2000 by the Clinton administration, and administered by the BLM, Bureau of Land Management, Ironwood National Monument supports some of the oldest trees in the world. Read this article posted with permission by R.J. Brenner.

Less than forty minutes west of Tucson, an inconspicuous treasure awaits exploration: Ironwood Forest National Monument (IFNM). When viewed on a map, its boundaries form what resembles a sideways ‘W’ encompassing 129,000 pristine acres of habitat. Officially designated a national monument in June 2000, it contains one of the richest collections of Ironwood trees, also known as Desert Ironwood ((Olneya tesota).

Arizona’s diverse topography and ancient cultural history offer endless opportunities to discover off-the-beaten-path roads and little-known travel destinations. The Sonoran Desert’s diversity rivals that of any other terrestrial ecoregion on Earth with its six ecological biomes — desert, thorn scrub, semi-desert woodland, Madrean evergreen woodland, interior chaparral, and temperate forest.

According to the National Park Service, the Sonoran Desert it is thought to have the greatest species diversity of any desert in North America with 560 fauna and more than 2,000 flora species. Even more striking than species diversity may be the tremendous variability in Sonoran Desert lifeforms and their adaptability to withstand the desert’s extremes. From soaring heat to frigid temperatures, from monsoon rain to extreme aridity, these are the hallmarks of this remarkable Sonoran Desert ecosystem.

A keystone species of the Sonoran Desert, Ironwoods grow in excess of 800 years, some as long as 1500 years, and grow nowhere else in the world. The tree’s wood is so dense it will sink when placed in water. Members of the pea family (Fabaceae), the trees can grow to a height of 45 feet and their leaves and lavender-colored flowers resemble those of a sweet pea.

In IFNM, the Ironwood tree is the dominant ‘nursery’ plant offering notable benefits to many desert species: roosting sites for hawks and owls, forage for desert bighorn sheep, protection for saguaro cacti, burrows for tortoises, flowers for native bees, dense canopies for nesting birds, and protection against sunburn for night blooming cereus.

In addition to the iconic ironwood, stands of palo verde and saguaro cacti blanket the monument floor beneath the rugged Silver Bell, Waterman, and Sawtooth Mountain ranges. Ragged Top Peak towers above the desert plain as the biological and geological crown jewel of the Monument. The desert bighorn sheep dwelling in the region are the last viable population indigenous to the Tucson basin.

Did You Know?
The difference between a National Monument and a National Park is the way they are created. National Parks require Congressional approval but National Monuments are established by Executive Order of the President. For more information visit the Friends of Ironwood Forest.