A little late, I would say

All I knew about El Morro was that Spanish explorers/missionaries and American settlers had carved their names on it. But I learned the native people were the first to leave their marks.

Some of the names must have been carved by pros, like Mr. Breckinridge (above) and Mr. Long (below).

But the reason anyone had come there in the first place was water. Rain and runoff collect in a pool at the base of the bluff. In the 1920s, ranchers added a dam around the pool to collect more water. Because, you know, there are those who believe extracting resources is more important than preserving ancient sites. Especially if the sites belong to non-white people.