Elwyn Creek

Elwyn Creek is a tributary of Mess Creek, which in turn is a tributary of the Stikine River in northwest part of the province of British Columbia, Canada. It flows generally west for about 25 km to join Mess Creek about 10 km north of Mess Creek's confluence with Taweh Creek. Elwyn Creek's watershed covers 173 km2 and its mean annual discharge is estimated at 3.34 m3/s. The mouth of Elwyn Creek is located about 16 km southeast of Telegraph Creek, about 60 km west-southwest of Iskut and about 93 km southwest of Dease Lake. Elwyn Creek's watershed's land cover is classified as 37.9% shrubland, 30.3% conifer forest, 15.2% barren, 7.6% snow/glacier, 7.1% herbaceous, and small amounts of other cover.

Elwyn Creek is in Mount Edziza Provincial Park which lies within the traditional territory of the Tahltan people.

Geography
Elwyn Creek originates in the middle of the Big Raven Plateau. From its source on the northwestern slope of Mount Edziza, Elwyn Creek flows about 4 km northwest past Tsekone Ridge and Pillow Ridge to the head of a vegetated canyon. It then continues to flow northwest through the canyon for about 5 km before flowing west inside the canyon for an additional 12 km to empty into Mess Creek.

Elwyn Creek's only named tributary, Kadeya Creek, is about 10 km east of Elwyn Creek's confluence with Mess Creek. It is about 14 km long and flows northwest into Elwyn Creek from near the western side of Mount Edziza.

Geology
Elwyn Creek contains a group of hot springs between elevations of 1350 and 1440 m called the Elwyn Hot Springs. They occur near the base of the Mount Edziza volcanic complex where basalt of the Nido Formation overlies Tertiary leucogranite. Thick deposits of tufa formed by the precipitation of calcite and aragonite occur at the Elwyn Hot Springs. In 1983, the springs had a maximum temperature of 36 C. Their existence may be linked to a shallow hydrothermal system driven by residual magmatic heat from the recently active Desolation Lava Field about 6 km to the east.

Elwyn Creek is the namesake of the Elwyn Creek Pluton. This is a body of intrusive rock at least 5 km wide exposed in Elwyn Creek canyon. The main intrusive rock comprising the Elwyn Creek Pluton is fine grained, slightly porphyritic leucogranite containing phenocrysts of sodic plagioclase. It is of Eocene age, having yielded a K–Ar date of 53.1 ± 2.4 million years. This suggests that the Elwyn Creek Pluton was formed by one of the youngest known igneous events in the Elwyn Creek area prior to the onset of volcanism of the Mount Edziza volcanic complex in the Late Miocene.

History
The historic Yukon Telegraph Trail crosses Elwyn Creek in Mess Creek valley. It was built to serve the nearly 3000 km Yukon Telegraph Line which was constructed by the Dominion Government Telegraph Service between 1897 and 1901 to send messages from Ashcroft, British Columbia in the south to Dawson City, Yukon in the north. The telegraph trail crosses other tributaries along the eastern side of Mess Creek, including Crayke Creek about 6 km south of Elwyn Creek.

Elwyn Creek was formerly called 14 Mile Creek which appeared on a BC Lands map published in 1929. Its current name was suggested by the BC Geographic Division to avoid duplication; it first appeared on maps in 1945. Elwyn Creek is named after Thomas Elwyn, a government agent who accompanied a Western Union Telegraph expedition in 1866.