Although the Rainbow Wall is the most prominent thing visible when looking into the recesses of Juniper Canyon, if you look north across the canyon, you will notice a massive chocolate colored wall riddled with cracks. This is the Brownstone Wall, and although the approach is long, the climbing is superb.
Approach: The standard approach to this area is to head up the drainage as per the Rainbow Wall, but head up and right, following a climbers trail to the base of Black Dagger. Other routes are up and right.
Beta/Updates: Another option for fast parties is to climb Geronimo and cruise across the slabs to the base and then also use Geronimo as a means of descent.