Armstrong Spring Creek is one of Montana's most coveted fly-fishing destinations. The spring-fed creek rises on the Paradise Valley's O'Hair Ranch at a year-round temperature of 52 degrees, and runs just a mile and a half of fishable water, with the Absaroka Mountains dominating the horizon, before joining the Yellowstone River.
Access is limited. The O'Hair Ranch charges a rod fee and encourages anglers to hire local guides to track the creek's abundant brown, rainbow, and Yellowstone cutthroat trout.
Midges, scuds, and eggs are recommended for winter fishing; baetis, midges, and sculpin in spring; PMD's, hoppers, crickets, and beetles are popular in the summer months; baetis and midges in the fall.