FIGURE 1. Smithsonian Grid Track, April 1966. 
* * f 
+ 
1 Inch = 1 = 60 Milos 
X — Entry and Departure Points 
Diurnal Travel 
Nocturnal Travel 
16 $* 
+ / 6 * 
+ A5-’ 
+ir 
-f/3* 
+ / 2 * 
