New snow hills based on the new hills

Some special case snow hills transitions
A smaller mountain trans variant used on some terrain

data/terrain-graphics.cfg

@@ -985,12 +985,14 @@
 {TERRAIN_ADJACENT_VERTICAL             T      !TNQq      tropical-forest}
 #{TERRAIN_ADJACENT_VERTICAL             F      !FNQq      snow-forest}
 #{TERRAIN_ADJACENT_VERTICAL             f      !fNQq      forest}
-{TERRAIN_ADJACENT          -171        mHhfF  N       grassland}
-{TERRAIN_ADJACENT          -172        M     !MX      desert-mountains}
-{TERRAIN_ADJACENT          -173        mb     !mbXh    mountains}
-{TERRAIN_ADJACENT          -174        HA     ks      snow-hills-to-water}
-{TERRAIN_ADJACENT          -175        HA     cZp\|/  snow-hills-to-water}
-{TERRAIN_ADJACENT          -176        HA     s       snow-hills-to-water}
+{TERRAIN_ADJACENT          -169        mHhfF  N       grassland}
+{TERRAIN_ADJACENT          -170        M     !MX      desert-mountains}
+{TERRAIN_ADJACENT          -171        mb     HSJ      mountains-small}
+{TERRAIN_ADJACENT          -172        mb     !mbXh    mountains}
+{TERRAIN_ADJACENT          -173        HA     ks      snow-hills-to-water}
+{TERRAIN_ADJACENT          -174        HA     cZp\|/  snow-hills-to-water}
+{TERRAIN_ADJACENT          -175        HA     s       snow-hills-to-water}
+{TERRAIN_ADJACENT          -176        HA     h       snow-hills-to-hills}
 {TERRAIN_ADJACENT          -177        HA     !HAX    snow-hills}
 {TERRAIN_ADJACENT          -178        J      !JX     desert-hills}
 {TERRAIN_ADJACENT          -179        ha     !haX    hills}