Add sidenote about Sierra tree species by altitude

src/content/notes/2024-eastern-sierra-trip.mdx

@@ -26,7 +26,7 @@ This was a short trip with modest ambitions.  I was in need of a few nights camp
 
 The goal for the first day was to make it to Bishop, a 5 ½ hour drive from the Bay Area.  My focus for much of the day was to put down miles and I don't have much to say on the first 4 hours of the day.  The Central Valley, Sierra foothills, and Yosemite passed without any notable stops.  I had places to be and the midday light wasn't presenting anything worth stopping for.  
 
-The aspect that stood out most was the smell.  Ponderosa Pine begin to enter the forest mix around 3000 feet elevation.  That pine smell, especially the dry flinty notes in late summer, is one of the most classically Sierra things to me, and the first encounter on any trip is a statement of "welcome home".  
+The aspect that stood out most was the smell.  Ponderosa Pine begin to enter the forest mix around 3000 feet elevation<Sidenote>In the confirming the conifer species, I found this illustration of [Sierra trees by altitude](https://www.csun.edu/science/sierras/trees/veg-1000/profile.jpg).</Sidenote>.  That pine smell, especially the dry flinty notes in late summer, is one of the most classically Sierra things to me, and the first encounter on any trip is a statement of "welcome home".  
 
 Once I made it past the eastern gate of Yosemite, I was done with the "get there" miles, and stopped to collect myself.  I was back in [Basin and Range](https://en.wikipedia.org/wiki/Basin_and_Range_Province) country.  The change going from the western slope of the Sierra to the eastern slope is quite abrupt.  The white granite is traded for red and brown country rock.  The pine for sage.  And the sense of being in the forest is replaced with that of being an open plain, facing a wall of rock.  I took a few quick shots, but my main interest was in making camp.