Mark Twain writes of the journey to Tahoe:

September 14–17 Tuesday – Sometime between these dates, Sam and John D. Kinney traveled to Lake Bigler (Tahoe), where they spent four days building a shack for a timber claim, then allowed their campfire to get away from them and were forced to flee from a wildland fire (not burning larger trees) [MTL 1: 126n3].

September 18 to 21 Saturday – In Carson City, Sam wrote his mother, Jane Clemens, of the events at Lake Bigler:
When we got up in the morning, we found that the fire had made its way to within 4 or 5 steps of us on the South side. We looked like lava men, covered as we were with ashes, and begrimed with smoke. We were very black in the face, but we soon washed ourselves white again [MTL 1: 124].
Sam’s letter also reflected homesickness:

September 18–30 Monday – (After Sam’s return from Lake Bigler and before the legislature convened on Oct. 1) In Carson City, Sam and George B. Turner (1829-1885) wrote per William M. Gillespie (1838-1885) to Orion, sending a “form for message” about a book of handwritten model forms. Sam explained, “From Hon. Chief Justice Turner—I sent your book by Dorsey, Orion—why the devil didn’t Turner send it to you himself while he was in the States?” [MTL 1: 128]. Note: Dorsey unidentified.

September 22–28 Saturday – This is the date range the MTP offers for possible second trip to Lake Bigler [MTL 1: 127n7]. See RI, Ch. 22 for details. Antonucci gives “no earlier than September 21 and ending no later than September 30” for such a trip [83]. Both sources give the purpose of the trip as completing work on their timber claim. See Oct. 25 to his sister. Both sources claim Twain made later trips to Bigler, but give no dates. The former source cites MTB 1: 180. Antonucci writes: