Fly Fishing Missouri River - Land of Giants

The Land of Giants is the short piece of the Missouri River that most people drive right past on their way to the more famous water downstream. It is a 4.6-mile reach running from Hauser Dam to American Bar Gulch at the head of Holter Lake, about 14 miles northeast of Helena, and for most of that distance the river is squeezed into a narrow gorge with high rock walls. Two dams upstream shape everything about it. Their reservoirs moderate the water temperature and load the flow with nutrients, so the reach behaves like a rich tailrace, and because Hauser is a run-of-river dam held within about a foot of full pool, the flow stays steady hour to hour with no daily peaking swings. The powerhouse is small enough that the dam spills frequently, and typical fishing-season flows of roughly 3,000 to 5,000 cfs make this heavy, powerful water in tight quarters.

The name comes from where the fish live. Most of the trout here are residents of Holter Reservoir that grow large on lake forage and push up into this short stretch of moving river, rainbows on their spring run and browns in autumn, with Beaver Creek serving as the principal spawning tributary. Because the reach recruits its fish from a lake rather than growing them in place, the averages are startling: 18 to 22 inches is a normal fish, 24-inch trout show up regularly, browns reach 27 inches, and fish from both species in the 24-to-30-inch class are not unusual. Only rainbows and browns swim here, and either one can be the fish of your season. Some regulars have noticed more trout appearing to stay in the river year-round instead of dropping back to the lake, though that is an observation, not a settled fact.

Day to day, this is nymphing water. Pink sowbugs and scuds, backed by size 16-18 Pheasant Tails and Frenchies on a two-fly rig, account for most fish, and streamers worked through the deeper runs are the other core approach. Dry-fly chances come and go with the season: pale morning duns and caddis in summer, hoppers in late summer, midges on calm winter days. The current is strong enough that most anglers size up, and a 9-foot-6-inch 6-weight rigged for nymphing is typical.

Getting in takes some commitment. Boaters launch at Gates of the Mountains Marina on Holter Lake and motor upstream into the canyon by jet boat or power drifter, then come back the same way, since there is no downstream takeout; marina access generally runs early March into November. On foot, you can hike down from Hauser Dam on either side of the river or reach the lower canyon through Helena National Forest via Beaver Creek Road and the Beaver Creek Recreation Area, on a rough 3.7-mile trail of loose rock. Wading is limited by the sheer size of the river and the gorge walls, so most fishing happens from an anchored boat, with edge wading near the dam the fallback.