The role of interpreters was crucial relations between Indians and whites. 
Lewis and Clark relied heavily on Sacagawea to help them pass safely
through Indian territories during their expedition of 1804-06.  Toby
Riddle (Winema) played a key role in peace negotiations during the Modoc
War of the 1870s.  Though she was the cousin of Modoc leader Captain Jack,
she was married to a white man.  Wishing to bring the two sides to an
agreement, she helped General Edward E.R.S. Canby arrange a peace council
with Captain Jack, and she acted as interpreter during the meeting.  In
the middle of negotiations, Captain Jack and his companions sprang up and
began shooting, killing the general.  Acting quickly, Toby Riddle disarmed
one of the Modocs and saved the life o f Alfred Meacham, the U.S. peace
commissioner who was also present.  Meacham later wrote "Her fidelity and
her heroism were unequaled; and when the attack was made, she sprang to
her feet, and by almost superhuman efforts saved my life."