How did the wagon train party communicate with people who were far away, (the donner party.)

The Donner party left Springfield, Illinois, in April 1846. Led by two wealthy brothers, Jacob and George Donner, the emigrants initially followed the regular California Trail westward to Fort Bridger, Wyoming. From there, however, the emigrants decided to leave the established trail and take a new and supposedly shorter route to California laid out by an unscrupulous trail guide named Lansford Hastings. Hastings was not at Fort Bridger at the time–he was leading an earlier wagon train along his new route. He left word for the Donner party to follow, promising that he would mark the trail for them.

Explanation: not sure but hope it helps