Matterhorn's range
I believe the answer is:
alps
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">matterhorn's range</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for alps that I've seen before include "With pals in great mountains" , "high areas" , "Slopes" , "European mountain range" , "Mountain system in south-central Europe" .)