One of the most prevalent place names in California is Willow Creek. By some estimates there are over 1100 Willow Creeks in California. Another common place name is Round Valley: There is one near Greenville in Plumas County; in Lassen there is one north of Susanville and in Modoc County there is a Round Valley just north of Adin.
But, the original Round Valley in this part of California is not called such anymore. Big Valley which straddles Lassen and Modoc Counties was originally named Round Valley.
It was John C. Fremont who named it Round Valley on April 29, 1846. Fremont wrote: “Here we found a region very different from the valley of California. We had left behind the soft, delightful climate of the coast, from which we were cut off by the high snowy mountains, and had ascended into one resembling that of the Great Basin, and under the influence of the same elevation above the sea; but more fertile and having much forest land and well watered.”
It was Adin G.McDowell who settled on the east side of the valley in 1869, and for whom to the town of Adin is named for, and referred to the locale as Big Valley. Even so, by 1880 some cartographers continued to designate it as Big Valley.