The Bagisu people or Bamasaba inhabit the western and southern halves of Mt. Elgon. On the west, the mountain spreads like the fingers of a hand with steep and narrow valleys between them. On the south, the land is broken and consists of a jumble of hills jammed against a high escarpment like a crumpled tablecloth. The escarpment fades gradually to a plain leading away to the northeast inhabited by the Iteso tribe.
The Bagisu speak a dialect of the Lumasaba language called Lugisu, which is fully understandable by other dialects, and is also understood by the Bukusu.
The Bagisu or Bamsaba undergo a circumcision ritual called the Imbalu. The ritual is held every two years during August.