The Northernmost Hot American Desert

Taking a break from trees for a little while, today's adventure will take us down past the evergreens into the realm of the parched desert.  Now, deserts (the non-polar kind) take many forms, and can actually be found in Canada as well as the United States and Mexico.  For a place to be a desert, it usually needs to have ridiculously low precipitation, meaning less than 12 inches of any kind a year on average.  Secondly, deserts not only need this, but they need to have at least some season of warm temperatures, low humidity, and barely any cloud cover.  This is important because precipitation and transpiration (plant life giving off excess moisture directly into the environment) need to be far outpaced by evaporation.  Basically, the sun needs to have a chance to work its magic so much that it pretty much wins.  Sounds awful, no?

Well, deserts can produce extreme conditions.  With little moisture in the air to moderate temperatures, they can get positively freezing on winter nights (mind you, I have been in 16 degree cold in bone dry Grand Junction, Colorado, and barely felt a chill).  During a hot summer day with no cloud cover, they can bake as much as 130 some degrees, with the ground reaching around 200!  Amazingly though, life has adapted to these conditions.  In fact, some life will live no where else when not taken care of by us gardeners and zookeepers.

The ground can be barren, and can even have dunes like we imagine deserts to look like.  For the most part though, in North America, you will see a lot of shrubs, yuccas, cacti, and some trees depending on the location.  The further south and lower in elevation you get, the more faux-tropical looking the vegetation and native wildlife gets.  Up north, where things are also higher, summers tend to be a bit cooler (90's on average instead of HEAT over 100 degrees) and winters will actually see a small amount of snow that stays on the ground from November until March or later.  The cold deserts are in British Columbia, Washington, Idaho, Oregon, the northern two-thirds of Nevada, Utah, Colorado, Wyoming, and northern Arizona and New Mexico.  The hot deserts are where elevations drop below 4,500 feet in interior California, the southern third of Nevada, a tiny little south western corner of Utah, southern Arizona and New Mexico, Texas, and a good chunk of northern Mexico.

Our northernmost hot desert, and a very nice one at that, the Mojave.

As you can see, I have drawn the approximate boundaries of what passes for Mojave desert life and landscapes.  I chose to do this myself because no two sources ever seem to agree on the boundaries of the desert.  I looked to explorations, the 4,500 foot contour, and even just the way the satellite image looks.  The two greener spots to the north and west of Las Vegas are mountains that rise up to about 11,000 feet and have a good snow cap for half the year.  The lighter spots are sand flats. The brown triangle pointing west which is north of Los Angeles is part of the Mojave basin, but has a landscape and vegetation more consistent with what coastal California looks like.

So, what does the Mojave look like?

Dramatic.  This was taken off of I-15 a few miles into Arizona from Utah.  The little darker green dot-like shrubs everywhere are the famous creosote bushes which dot the landscape heavily from California to Texas. They are evergreen, some are extremely ancient (the oldest is apparently 10,000 years old, constantly re sprouting from the same root mass), usually the only thing growing in flatter parts, and are a good way to tell if you are in a hot desert; they are a bit sensitive to colder temperatures lasting longer than a few days.  The other small, but lighter green/sage shrubs are sagebrush.  You might also notice a few weird tree-like looking things with multiple branches and what appear, from this distance, to be pine needle globes.  Those are Joshua trees, and they are pretty much only found in the Mojave desert.  Check out this map to see that I am not kidding.

What does one look like up close and personal?  Well, try out a huge stand of them:

I lost my pictures of Joshua Tree National Park, but I fully intend to go back there and get some better shots.  The park is a unique place; the Mojave and Sonoran deserts meet there and feature some really amazing plant communities, including most of the remaining California Fan Palm oases.  I did manage to take a few close ups that will suffice for the meantime, though.

  That was taken behind the first rest stop you get to in California when coming from Nevada on I-15.  Again, you can see that the bushes with leaves on them are creosotes, with a great example being in the bottom left.  That gray lump of rocks on the top right?  Hardened lava.  The Mojave has tons of it, along with some volcanoes and cinder cones.

The Mojave is by no means limited to these species.  If you walk along an average segment of it, you will find Joshua trees, creosote bushes, Mesquite trees, prickly pear cacti, barrel cacti, yuccas, sagebrush, grasses, California poppies, primrose, sacred datura, and the list goes on.

The place has some sandy spots, mostly dried out lake bottoms:

These are called playas, the Spanish word for beach. Sometimes they can be very salty, like on the bottom of Death Valley.  Otherwise, they are pretty much just sand flats, like good old Ivanpah Lake where this shot was taken.  I-15, just inside of California near Primm, Nevada.

Yes, the Mojave can also be barren and rocky.

But then, it can also be incredibly lush, even long after the winter rains (all five inches of them) have long since gone under the ground or into the air again.

It can be an interesting place to explore, especially from its fun de-facto capital of Las Vegas!  Any time of year can bring someone here, but the best time would depend on what you want to get out of the experience.

Spring: Lush green plants, a thin mat of velvety grass over what would normally be sand and pebbles.  Cooler weather (70s or so) and decent cloud cover.  The desert as a complete shock.

Summer: Scorching temperatures (upper 90s-120s) when skies are clear, occasional intense thunderstorms that pass within seconds of starting, a muted brown landscape past early june.  The desert as the typical desert.  Kind of fun watching the car thermometer climb and climb.

Autumn: Lower temperatures and the landscapes of summer, sometimes even drier.  The cottonwoods along streams turn yellow.  Palo Verdes get their leaves back (a reverse tree, really).  

Winter: Things slowly turn greener, overcast days can happen, and sometimes... snow can blanket the land.  The days will mostly be in the lower 60's at the peak of the season, the nights much cooler.  A bleak time to visit, but a good time to travel in and out of the desert and see the contrast with the other two deserts it borders.  The place is much, much warmer than the surrounding areas.  Take a look at what you can have outside, in the ground, at St. George in Utah:

Yes, St. George is zone 8a.  You know, like Mobile, Alabama or Myrtle Beach.  Even in 2008, when the entire country was under a cold spell, and nearby Cedar City was sitting at 20 degrees, St. George was sitting at 50.  Driving south in other parts of the United States brings gradual change.  Driving south on I-15 into Washington county is like heading into a different world almost immediately.  Right around the Pintura exit, one drives out of the junipers and into cacti and yuccas.  A mile onward, one sees the first Joshua tree en route, a small, scrubby thing.  People grow Italian cypresses around their homes.  A few more miles down, if it is winter, the snow just vanishes and red earth is everywhere.  A few more miles past that, you notice how the temperature has risen about 10 degrees since back in Pintura and keeps rising.  An exit with a Texaco station pops up, and is surrounded by California fan palms.  Red cliffs and mesas rise in a landscape that seems to go on forever.  It's a part of the drive I look forward to every time.

The edge of the Mojave is every bit as interesting as the desert itself.  One can climb into or descend down upon a different world.  Once again, you can even see the Ponderosa Pine snub its natural range.

Think this is in Colorado or Wyoming?  Think again.  They are 3,800 feet up on the road between Hurricane and Zion, in Washington County.  Speaking of which, that route, Utah 9, is probably one of the most amazing ways to enter the Mojave desert.  Pictures do not do it justice.

Zion National Park is one of the most amazing places in North America.  Drive in on Utah 9 from the west, and you get a vantage of grandeur from the end and floor of the canyon.  Try it at noon.  Drive in from the east, and you come out of a tunnel and thousands of feet above the canyon floor.  Try it at late afternoon, as when these pictures were taken.  It's quite the experience.