On the west side of the river, across from the left side of Lost Angel. The base has an excellent view of the crux of Strange Cargo. Conversely, the routes on Lost Angel which start by or in the river have a good view of the heavily chalked Spider's Den.
To get there, cross the river on a 6x6 beam about 100 feet downstream of the start of Autumn. Take the prominent trail right, then cut back left after about 100' to the base of the crag.