The 8,007 ft (2,441 m) peak is sometimes referenced as Iron Mountain #1 or Big Iron, was originally called Sheep Mountain by the early miners in San Gabriel Canyon because of the large bands of bighorn sheep that roamed the slopes.

According to Will Thrall, there was once a USFS plan to change the name back to Sheep Mountain in 1940.

There are no maintained trails, the summit is seldom visited, and the climb is of about 6000 vertical feet (1,800 m), much of it at a 30° to 50° angle on loose soil, decomposed rock, or through brush.

Some approaches to the summit require high degrees of rock-climbing skill.

The south mountain slopes in summer are directly exposed to the sun.