Native Americans, including the Yakama Tribe inhabited the region surrounding Ahtanum Creek long before the arrival of Europeans. The band living along the creek, known as Ahtanumlema, were considered to be one of the more important groups within the tribe. While the creek still lied within Oregon Territory, Catholic Fathers Louis D'herbomez and Charles Pandosy were sent to the area by François Norbert Blanchet, who was Bishop of the Archdiocese of Oregon City at the request of native leaders. Father Pandosy first served in missions near Richland and Ellensburg before constructing St. Joseph's Mission in 1852 with Father D'herbomez along Ahtanum Creek near what is now Tampico. This location was chosen because of its location within the main summer camp of Chief Kamiakin. The missionaries and Yakamas worked together to build the first irrigation canals in the area. The relationship between the two groups was such that Kamiakin and others brought their children to the mission to be baptized. In 1854, Father D'herbomez was replaced by Father Pierre-Paul Durieu who would compile a dictionary of the Sahaptin language. The original mission was burned down in 1855 during the Yakima War by U.S. soldiers who believed the missionaries were conspiring with the Yakama Tribe. The mission was rebuilt in 1867. Union Gap was established as Yakima City along Ahtanum Creek near its confluence with the Yakima River in the 1860s and became the county seat in 1870. In 1885, the Northern Pacific Railway established North Yakima four miles north of present-day Union Gap because the railroad considered the then-current settlement to be too swampy and too close to nearby ridges. North Yakima was incorporated and became the county seat in 1886. A wildfire burned near the North Fork of Ahtanum Creek in 2009.
Human use
Water is pulled from Ahtanum Creek to irrigate of land upstream of the gauge in Union Gap. Fishing is popular along the creek, with fly fishing, baitcasting, spinning all being successful. The upper portion of the creek's watershed lies within Ahtanum State Forest, which is managed by the Washington State Department of Natural Resources. The forest has an area of that has numerous campgrounds. Seasonal hunting and snowmobiling are also popular.
Ecology
Being located in the rain shadow of the Cascade Range, Ahtanum Creek has a riparian zone that serves as an important habitat for animals living in the region. Endangered species that utilize the creek include steelhead trout, bull trout, Chinook salmon, and coho salmon. The Yakama Tribe completed a restoration project at La Salle High School. This project included strengthening three areas of the creek bank that were prone to erosion and reintroducing native plant species such as coyote willow. Along with this, two backwater channels were created and of soil were removed from the flood plain. These changes reconnected that stretch of the creek with its flood plain and provided areas for young fish to be reared. The North Yakima Conservation District installed fish screens on five water diversions between 2002 and 2006.
