Mormon History, Sep 9, 1845. Tuesday.

[William Clayton Journal] At 2 P.M. met in the upper room of the Seventies Hall with the Council of Fifty. The subject of sending a company of Saints to the West next spring was talked over, and the following motion of by W. W. Phelps: "Moved that the President select such a portion of this Council as he may choose to remove west, and they select and organize the company subject to the final revision of the President." A vote was taken and the motion was carried unanimously. The following motion was also put and carried unanimously "That a committee of five be appointed to gather all information relative to immigration and impart the same to this council, and those about to emigrate when called upon."
Daniel Spencer has returned a few days ago from the West. He reported in substance as follows: Their mission was to the Seneca Indians. They proceeded to about 500 miles up the Missouri River. They there met brother [Lewis] Denay and from him learned that [Jonathan] Dunham was
dead. They tarried five weeks with the Stockbridge tribe. This tribe manifested great kindness towards them and the Mormon people. They have considerable knowledge of the Mormons and of what is going on; their interest seems to be identified with ours. From Denay they learned that the Che[r]okees had given permission for any number of our people to settle near by them and were willing to lend us any assistance they could or to go west with us to explore the country. George Herring has been with several tribes and says they are all friendly and seem to understand what is going on and are ready to render us any assistance they can. Many of the Stockbridge tribe are joined in with the Baptists but are dissatisfied. Their chief expects to be here about the 6th of October. They preached to them and they seem satisfied with our doctrine. From what Brother Denay said they concluded it unnecessary to go to the Seneca tribe, they learned that Denay had accomplished what they were sen
t for.

[source: George D. Smith, An Intimate Chronicle; The Journals of William Clayton, Signature Books in association with Smith Research Associates, Salt Lake City, 1995, http://amzn.to/william-clayton]