Tenmile Creek rises near the top of the Continental Divide on the east slopes of the Rocky Mountains, specifically the Lewis and Clark Range.

The lower watershed consists of the final 5 miles (8.0 km) of the stream, which travels over prairie and through residential and retail developments in and near the city of Helena, Montana before reaching its outlet at Prickly Pear Creek.

[4] Irrigation, primarily for farmland, draws heavily on water in Tenmile Creek, leaving the stream dry at points.

[2] Arsenic, cadmium, copper, lead, nitrate, phosphorus, and zinc are released into the stream when water flows over or through mines or main tailings and reaches Tenmile Creek.

[10] The city also built and maintains Chessman Reservoir and Scott Reservoir near the stream's headwaters, which retain excess water during periods of high precipitation, and release this water during periods of high demand (usually later summer and fall when stream flow is low).

They also argued that the city should take more water from the nearby Missouri River so that Tenmile Creek could sustain greater flows.

[13] The following year, the Bates Land Company put 1,212 acre-feet (1,495,000 kl) of Tenmile Creek water up for sale at a price of $9.6 million ($12,740,629 in 2023 dollars).

Between 2000 and 2008, the city of Helena spent about $415,000 ($587,286 in 2023 dollars) to create a 432-foot (132 m) wide vegetationless buffer zone on either side of portions of the flume to reduce the likelihood of fire damage.