Originally called Deep Creek, Cedarville was a camping place for wagon trains settled about 1864. William Cressler and John Bonner were running a trading post by 1867; this historical building stands today in Cedarville Park. These men were instrumental in developing Cedarville. Cressler and Bonner built the first road over Cedar Pass, which connects Surprise Valley to Alturas and the rest of Modoc County. By 1880 Cedarville's population was 220 and was the largest town in the valley. Historic buildings still line Main Street, housing many of the community's businesses. Tourists may also visit Louieville, a collection of refurbished pioneer buildings from the valley, on display at the Modoc County fairgrounds.