Quoting Wendell Huffman :

> I'd sure like to learn more about Fremont's route(s) from Lassen's
> ranch to Klamath Lake and back in 1846.

Unfortunately, this goes for the entire Third Expedition of the great "Pathfinder": not only did he fail to file a report, he prohibited other participants from keeping journals (tho Ed. Kern did), and most of what we know about this most important adventure, which first crossed the Hastings Cutoff, comes from documents written later and much later--all after Fremont's conviction for mutiny during the Mexican War.

I did find one document that escaped this web of secrecy--ironically, trotted out by JCF's father-in-law to enhance The Hero's reputation but revealing that starvation was a typical feature of Fremont's leadership.

KING, HENRY, TO DEAR PARENTS, 30 MARCH 1846 , IN "APPENDIX: COPY OF HENRY KING'S LETTER FROM CALIFORNIA, ," CONGRESSIONAL GLOBE, VOL. 16 AND APPENDIX (29:2), 137-38.

King, Henry, to Dear Parents, 30 March 1846, in "Appendix: Copy of Henry King's Letter from California, ," Congressional Globe, Vol. 16 and Appendix (29:2), 137-38. Travels at "a pretty swift rate" of about three miles an hour. "very soon our animals began to break down. (I rode down three horses from Westport to the lower point of the Cordilleras ridge of mountains.) At the Great Salt Lake, Frémont took King, five hunters, and "our cylinder boat" to Antelope Island, fording over a solid salt crust that was "the best imitation of ice I ever saw." A storm drove them back to Antelope Island, where they spent three days surveying "bearings to the various islands." "We then went to camp again, and started on our journey two days afterward. In about two weeks afterward the captain with seventeen men started out to explore the (so called) Great Desert, and the balance of the party, of which I was one, came down Mary's River and so across the country" to the Cordilleras, where they waited for the captain. After meeting, Frémont went from "Trout Lake" to the Sacramento while thirty men went to the "point of the mountains." Run out of food and spend four days without any: "My hip bones became so sharp that I could not sleep for several nights." Eat about 25 horses and mules. [138] Wait on Frémont's orders for promised provision at point of the mountains for twenty days, but Frémont gets lost trying to cross the mountains, "got into the snow and lost everything, animals and all," and gave up. After reuniting head for Monterey but two "Spanish officers" bring a proclamation from the governor ordering them out of California or be driven out by 200 troops: "The captain sent him word to come on." Run short of provisions "and had to retreat." Camped near the head of the Sacramento: "I think it very likely that we will return yet, and go down through California; peaceably if we can, forcibly if we must."