Captain Oliver Cromwell Applegate was an Oregon-native born in 1845. He helped open the Applegate Trail and edited the Klamath Republicani> newspaper. In 1898 he worked as a United States Indian Agent for the State of Oregon and was in charge of the Klamath Reservation. During his 7 years of service to the reservation, he helped establish its lands and irrigation which added to its wealth. Captain Applegate served as a scout in the Modoc War. He died in 1938 at the age of 93.

The Denny Creek marker commemorates the camping site of pioneer John Fremont during his 2nd journey of exploration (1846). The camping site was attacked by Indians, and Fremont named the creek after one of the three men he lost that day. Presently, the marker for this location can be found along Highway 140.