Thanksgiving in California / At the Cabin, 1849 — D.W.N.
Or maybe it was really 1850. In Daniel W. Nason’s (unpublished) memoir of his two years in California, written twenty years later, he recalls the Thanksgiving feast he had with his friends in November 1850, even though he labels the poem 1849. But no matter. Whatever the year, the memory of “chowdered clams” and “mountain dudes” was still bright.
For more about Daniel Nason and his experiences in the Gold Rush, see this article from the Massachusetts Historical Society.

Three hardy sons from New England's shore, With bronzed face and scarred hands, Sat down to talk old matter o'er, And feast on smoking chowdered clams. Amid the wild California scenes, 'Mong stately pines our cabin stood; On rolling hills and deep ravines, Where roving deer and grizzlies brood. Thanksgiving Day we here enjoyed, The bivalves from the Merrimac; While all about us wild and void, We pioneers our jokes would crack. Three thousand miles from home and friends Was nothing to these roving boys; 'Twas digging Gold in wooded glens, Those mountain dudes were thus employed. Free from all creeds, or labor strikes, And every political clan; Freedom was not in petty fights, Revolvers backed up every man. We thus look backward two score years To that log cabin on the hill; The boys still live, those pioneers, I hope, and wish, they always will. Whatever is on your menu, I hope you enjoy a bountiful and satisfying Thanksgiving Day.