Day 5: Weed to Boise

 Farewell Cascadia

Our day began with clearing rain and packing up.   Clouds danced and gathereed around Shasta.  Then we took to the road:  our first "long haul."   We had originally planned to stay at the southern edge of Oregon for as long as possible and then take dirt roads up the Alvord Desert.  After our times on much shorter dirt / gravel roads around Shasta and reports of periodic washouts, we chose the safer option.

  

Most of today was spent of 2-lane roads through very sparsely populated parts of the country.  A lot of mountain passes and deep valleys and rivers we had only barely heard of.  The journey up US 97 took us past many lava flows between where the pines meet the sagebrush of the valleys.  Overall more climbing the descent, but plenty of both. We were eventually on to a large plateau - definitely East of the Cascades now -  the Back arc region - often neglected by intor texts, and yet essential for defining the kind of Continent you have.  This one has seen it all htough presently is dominated by lava flows and Basin and range extension, which we will be driving through for most of today

Hwy 140 Basin and Range

Oregon was celebrated with a photograph and high five .  . our first new state after over 1000 miles.  California is freaking long from it's south - north border.  We Turned East at Klamath Falls toward Highway 140- a road that hugs the state' southern border.  The road begins by going up a bucolic green river valley slowly making its way inland past very tiny towns.  Then the ridges.  You cross at least 3 passes.  This whole reagion is dominated by Fault block mounatain building /  basin and range faulting.  As the crust extends horizontally, sections of tilt creating numerous valleys and ridges  all roughly paralle to one another for 100's of miles.  We are on the Northern Edge of the Great basin province where the relief between ridge and basin can be 1000's of feet (over 11,000 between Death valley and Telescope peak).  Whereas much of Nevada is fairly dry the elevation here and some favorable location with respect to storms graces this area with more rainfall and greenery. 

US 395 and the Abert Rim

After Quartz Summit Hwy 140 descends in earnest into a much deeper valley full of many lakes and few rivers.  This usually indicates groundwater flow, not surprising given the depth of this basin and the permeability of the rocks around us (mostly fractured lava flows and alluvium).  We are now deep in alfalfa country and the temperature are warming up a bit.  We gas up in Lakeview.

 We are the bottom of a fault escarpment here that runs for 30 miles to the north.  Here in lakeview you can see hillside get flatter and then steeper marking the likley location of the main fault trace.  Normal faults are often hard to spot, becase they form unstable slopes that subsequently erode, mass-waste and cover the fault trace.  thanks in part to the resistant rocks and dry climate the Abert Rim is easy to spot.  2,000 + feet of vertical relief capped by a basalt cliff.

The origins of these basalts are bit up for debate.  While clearly a partial melt of the mantle, how that melt took place is not certain.  The most popular hypothesis is rooted in "Plume theory"  and suggests a blob of hot material 100's of km in the mantle made its way to the surface and melted the lower crust in spectacular fashion.   The less popular but equally interesting "plate theory" suggests that a large tear on the slab of ocean lithosphere subducting under N.America made way for asthenosphere mantle to heat up the lowest crust.   We'll spend the rest of today and all of tomorrow exploring various flavors of the "Yellowstone Hotspot"

Abert lake is now to our left, an endoheric basin in which water exits only by evaportaion.  When the water evaporates it leaves its chemical weathering products behind in the form of Halites, Gypsums and Calcites.  The hypersaline body also has a distinct smell from the microbial life within it.  It feels as if standing on a another planet here, all the salts and barren lands.   

Beyond Abert lake we have a second endoheric lake, Alkali Lake, which has managed to build up a sandy shoreline at some point in its past.  We end up stopped for about 10 minutes for construction and get to talking to the flag waver.  Turns out he's got a bit of geology in him as well and supervised the protection of native American artifacts for Archeological digs on Chumash land.  Very friendly curious fellow who made our traffic delay breeze by.   Also a reminder that we not the first ones here.  This is Paiute Land we are crossing here, and some acknowledgement seems due.

The Malheur Canyon

Continuing north we go into increasing desolate and empty terrain.  Mileage to anything resembling a town is over 70 at some points of our journey.  No trees, just distant mountains.  A lot of the country is this lonely in some way.  For us it is a change of pace to say the least.  We drive through Burns, a town made famous for the militia guys storming and occupying some National wildlife refuge building and then failing to realize how cold it got here in winter.  I spent the next hour trying to contemplate how exactly this development made sense, and could only conclude that any efforts to understand would take me off script for this blog.

Soon we were climbing again and up and over 2 mountain passes:  Stinkwater pass and Drinkwater pass - clearly both mapped by a thirsty party.  below the second we entered Mountain time and set our clocks ahead.  Then the land rose up around us and we stayed flat.  We were following the incised meanders of the Malheur river as it headed East to Join the Snake river and eventually the Columbia.  Older than the rise of the land, this river had cut down from a meandering steam into the basalts to create a mini canyon of wonder.

Our own private Idaho

The last few miles of Oregon have us deep in onion farming country near the confluence of the Malheur and Snake rivers.   Heavy irrigation and a slightly sweet burnt sense in the air.  It seems to go on forever.  So much of Oregon has no limits.

Idaho hits us with a sudden increase in traffic speed and intensity as we cross the Snake river.  Almost immediately we are aware that this is near the Boise-Nampa "Megalopolis."  This "Portland of the Rocky Mountains" is enjoying explosive population growth as people flee the expensive west coast cities for something where the dollar goes further but creature comforts still exist.  

We climb out of the Snake River valley onto a plateau full of farmlands, poorly-planned subdivisions and trailer parks.  I really wish we had packed the B-52's cassette . . . anyway I can't resist posting this song.  

Boise is an absolutely charming city nestled in the Boise river valley full of cute cafes and bike paths and other young Millennial comforts.  It also benefits from a remarkably intuitive street layout with well marked signs.  I honestly wish we had more time to explore here as there seems to be all sorts of cool stuff within walking distance of our Bed and Breakfast place.  Anyway until tomorrow . .