From Sacramento, "They steamed inland on the Flora to Marysville on the Feather River..."  (pg 356 Scharnhorst V1)

From Marysville,  "They then took a stage to Grass Valley..." 

Scharhorst reports that Twain spent the night in Meadow Lake, a mining camp  where Orion had previously lived.  It is currently a ghost town on the map called Summit City.

October 11 to November 27 Tuesday – Sam and Denis McCarthy, former part-owner of the Territorial Enterprise, (who Sam now labeled “The Orphan,” quickly organized a lecture tour in California and Nevada. (Lorch gives strong reasoning that the subsequent lecture tour was most likely organized well before this Oct. 2 debut [35-6]). The lecture, titled “Sandwich Islands” made sixteen engagements between these dates at locations where Sam was well known [Sanborn 298-9]. Dates in Silver City, Dayton, and Washoe were canceled.

October 15 Monday – Sam and Denis McCarthy traveled by riverboat to Marysville, California (named for Mary Murphy, a survivor of the Donner Party). There, Sam gave the lecture “Sandwich Islands” at Maguire’s New Theatre [Sanborn 299].

October 17 Wednesday – Sam’s article dated “Sept. 24, San Francisco, An Epistle from Mark Twain THE QUEEN’S ARRIVAL / ALPHABET WARREN / MISC.” ran in the Daily Hawaiian Herald [Schmidt; Camfield bibliog.].

October 20 Saturday – Sam and McCarthy traveled by stage through gold boomtowns, Timbuctoo, Smartsville, and Rough and Ready (in modern days nearly empty). Sam gave the lecture “Sandwich Islands” in Hamilton Hall, Grass Valley, California. The Grass Valley Daily Union reported:

October 23 Tuesday – Sam gave the lecture “Sandwich Islands,” in the Nevada Theatre in Nevada City, California, a short distance from Grass Valley. Sam stayed at the National Exchange Hotel. The local newspaper Transcript wrote: “Mark Twain” as a lecturer is far superior to “Artemus Ward” or any of that class….We bespeak for him large audiences wherever he goes [Sanborn 300].

October 24 Wednesday – Sam and McCarthy rode horseback to the old mining camp of Red Dog, California and gave the “Sandwich Islands” lecture at the Odd Fellows Hall.

October 25 Thursday – Sam’s 24 th letter to the Union dated “Kilauea, June 1866: A NOTABLE DISCOVERY” ran in the Union:
FREE-AND-EASY FASHIONS OF NATIVE WOMEN

October 26 Friday – Sam and McCarthy stopped to see Meadow Lake City, also known as Summit City, Ca., the highest of the gold mining districts at 7,100 feet and the place where Orion Clemens had briefly tried a legal office. They arrived at 9 PM [Schmidt: article from S.F. Bulletin, ran Dec. 6].