Montana Fly Fishing 3 min read

DIY Guide to Fly Fishing the Ruby River in Montana

Ken Sperry

Posted by Ken Sperry

February 28, 2024

Upper Ruby River

The Ruby River is an excellent trout fishery in Southwest Montana and begins its journey in the Gravelly Range. As it runs through this region of Montana, it flows into the Ruby Reservoir.

At the reservoir, the Ruby River takes on a new terrain as it finds the Ruby Range on the south and the Tobacco Root Mountains on the north. The river finds its conclusion at the confluence of the Beaverhead River near Twin Bridges.

For the angler looking for solitude and breathtaking scenery, the Ruby River will not disappoint. 

About Ruby River

Fly Fishing the Ruby River in Southwest Montana

Best Places to Fish the Ruby River

The two distinct sections of this river come with options for the fly-fishing angler. If you prefer tackling rainbow, grayling, and cutthroats, the upper stretch should be your destination, while the lower section offers prime brown trout fly fishing opportunities.

There are plenty of access points to the upper stretch in the Beaverhead-Deerlodge National Forest. The lower section is known to be more access-friendly. We will go into more detail on access in the coming paragraphs.

The population of rainbow trout in the upper section is of average size, although larger rainbow trout can be found. The average brown trout measures 10-14 inches in the lower section. However, it is not unusual for brown trout to measure between 18 and 20 inches.

Upper Ruby River Access Points

Let’s look at access points on the Ruby River in more detail. From the origin of the river to Ruby Reservoir, the upper stretch, the easiest access will be found on the national forest land. The Cottonwood Campground south of Alder, MT (see map above) is a great place to explore the Upper Ruby. Outside of this area, access is practically impossible due to private land restrictions. The exceptions to this are the select few bridge crossings, but even these are difficult.

The difficulty in access once the river leaves the national forest land is due to it flowing through private land. The landowners in this region are not angler-friendly and have constructed high fences to thwart angling opportunities. The bridge crossings, which normally would afford opportunities for fishing, are difficult for the same reasons. High fences that would need to be scaled are found at these crossings.

Lower Ruby River Access Points

The lower section, particularly below the Ruby Dam, offers numerous public access points. Many bridge crossings will not require an angler to scale a tall fence to access the river.

Below the dam, thick brush lines the banks throughout this section, making wading a bit difficult. The river opens south of the Vigilante FAS as the landscape changes to open, arid agricultural land.

Ruby River Map and Fishing Access Sites

Map of fishing access spots on the Ruby River in Montana

Get Directions to the Fishing Access Points shown above with the DIY Fly Fishing Map

Ruby River Fishing Tips

With relatively light fishing pressure, particularly above the reservoir, the trout are considerably less finicky in the Ruby than in other heavily fished rivers in southwest Montana, like the nearby Beaverhead River, Big Hole River, Jefferson River, and Madison River.

Small (size 16) Adams, Royal Wulff, Stimulator, Elk Hair Caddis, or X-Wing Caddis dry flies have proven effective on the upper section.  A size 16 beadhead Pheasant Tail or Hares ear nymph with a soft-hackle dropper will do the trick for nymphs.

If you find yourself fly fishing the river during the later summer months, small tricos work well.

Grasshoppers are found throughout the lower section, so hoppers are the fly of choice. Other patterns that fare well for the larger browns include various minnow patterns and woolly buggers.

Gear Recommendations

A 3-wt or 4-wt rod is sufficient for the smaller trout in the upper Ruby River, while a 9-foot 5-wt fly rod with a floating line is perfect for the larger fish you may encounter on the lower Ruby River. 

Stream Flows and Current Conditions

It’s important to check stream conditions before heading out to fish to ensure the river is not too high or low. Available USGS stream gauges for the Ruby are provided below and available for easy access in the DIY Fly Fishing App.

Ruby River above reservoir near Alder, MT

  • Streamflow: 467 ft³/s
  • Gage height: 3.98 ft
Streamflow GraphGage height Graph

Ruby River below reservoir near Alder, MT

  • Streamflow: 492 ft³/s
  • Gage height: 4.05 ft
Streamflow GraphGage height Graph

Ruby River Fishing Reports

Several area fly shops publish a Ruby River fly fishing report. A few to check out are listed below.

Trip Planning Tips

The Ruby River is located in a more remote portion of Montana. The closest interstates are I-15 and I-90. Hotels are found scattered throughout the river, with Twin Bridges having a small selection. Camping sites are available on the national forest land and at various access sites on the lower stretch.

In closing, it must be mentioned that the private landowners along this river are not known to be angler-friendly, so please respect their property rights. There are public access spots for us to use.

Looking for more places to fish in Montana? Check out our DIY Guide to the Best Fly Fishing in Montana

Feature image by Mike Cline