The second expedition returned to New Helvetia in 1846 , again with Piupiumaksmaks and Tawatoy , along with Lenape Tom Hill among others . Conflict was brewing in the region as the Conquest of California was then in full force . Initial reports among American settlers and military figures of the Walla Walla expedition claimed the force was over a thousand in size . However Piupiumaksmaks declaimed military action and requested peaceable relations and for further commercial transactions to commence . An estimated two thousand cattle was purchased . In addition , ten Walla Wallas were recruited to fight alongside Americans as scouts . When the expedition returned to the Columbian Plateau , it contained members will with measles . The disease was spread across the Pacific Northwest and was a major cause of the Whitman massacre that occurred shortly after the expedition returned
Whitman massacre
Whitman massacre
Walla Walla expeditions