He was trading Ivory for Cloth with the Ethiopians and then trading cloth for ammunition.
The cloth called "Maraykaani" was apparently the most coveted thing by all native Africans including Somalis
Ugaas Yaro would trade all the ammunition and guns possible for the cloth he traded for Ivory with the Ethiopians.
That's how Marehan was able to circumvent the heavy embargo/blockade by the British into any imports finding their way in Marehan country.
Chief Yaro Ali is the grandfather of the current Marehan/reer Hassan chief Ugaas Mohamed Ugaas Hassan Ugaas Yarrow.