Draw the real mountain, not a triangle

1. Find a photo of the actual place from the angle locals know best.
2. Trace only the skyline: one continuous line, no shading.
3. Simplify in passes, removing one bump at a time. Stop just before it stops looking like that mountain.
4. Check it at 24 px. If the silhouette still reads, you've kept the part that makes it specific.

Show the client the photo next to the mark. That's the story they'll repeat to everyone else.