June Fishing on the Ruby River

June weather, stream flows, and summary

Fishing on the Ruby River in June is more of a rarity than it is a regularity. Draining the Gravelly Range in southwest Montana, then flowing into Ruby Reservoir, the Ruby River in June experiences a prolonged snowmelt runoff combined with water releases from Ruby Dam that do not always line-up with the desires of anglers. It is best to assume the Ruby River is not a viable option until the last week of June—and even in most years fishing the Ruby River in June is a roll of the dice. 

Above Ruby Reservoir stream flows may drop below 300 cubic feet per second (cfs) by the middle of June, however even at stream flows above 250 cfs, accessing the river is difficult for most of its reach above the reservoir. Below Ruby Dam, for most of June stream flows average above 300 cfs. Although several public access sites exist on the Ruby River below Ruby Dam, at stream flows of 300 cfs and higher avoiding private property is impossible. 

The weather in June is varied. Early June sees average daily high temperatures hover around 70 degrees F while later in the month average daily high temps tick close to 80 degrees F. Later in the month the prevalence of sunny days far out-weigh overcast days. 

Fly fishing the Ruby River in June is a rarity and best reserved for anglers who can shore up access via gaining permission via private property—which is very difficult to do. 

June fishing: what to expect

In most years, June fly fishing on the Ruby River is a non-existing proposition. During the first two to three weeks of June, the river is still in the heart of its snowmelt runoff mode and stream flows above and below Ruby Reservoir are well above levels conducive to fishing and public access.

In early June the river’s stream flows are the highest of the year, often peaking well above 800 cubic feet per second (cfs), nearly three times the stream flow for fishing to be safe, reasonable, and to avoid trespassing. Do not expect to fish the Ruby River until flows drop below 300 cfs, which rarely occur in June. 

Should stream flows allow for fishable conditions, a typical day on the Ruby River in late June begins with managing expectations. Because the river is often high and fast, leaders are short and stout—it is common to fish 7-foot 0X leaders with short tippets. 

If the river drops and clears and becomes fishable by the last week of June, two-fly weighted nymph rigs will produce fish as the river transitions to clearer water and lower stream flows. For nymphs, choose large black or brown patterns in sizes 2 to 8. For streamers, choose a tippet no less than 10-pound breaking test. 

By the last week of June hatches of caddis and Pale Morning Dun (PMDs) mayflies can occur. If they do occur, they will be strong and fish will feed voraciously. But stream flows need to be low enough to safely and legally fish the river. 

Where to find June trout on the Ruby

Ruby River trout during June are found mostly along the banks or in very soft water in- and around structure. Because early June sees the river’s highest flows and most muddy water of the year, finding trout in early June is very tough and most anglers avoid the Ruby River in June.

In some years by late June, typically not before June 25th, stream flows may drop below 300 cfs and clarity will improve enough that the river becomes fishable. If this occurs, caddis, Pale Morning Dun (PMDs) mayflies, and Yellow Sally stoneflies can hatch in abundance. Because caddis and Yellow Sally stoneflies require structure from which to hatch, trout will be found near willows, submerged rocks and branches, and other structures. The fast and high flows in late June force trout to hang near structure and in slow water. Eddy-lines, foam-lines created by eddies, and any slow water are places to find trout on the Ruby River in June. 

Important June hatches

The Ruby River in June can experience a plethora of caddis, Pale Morning Dun (PMDs) mayflies, and Yellow Sally stoneflies in June. However, stream flows and clarity often prevent reasonable fishing conditions from occurring. 

Beginning with Yellow Sally stoneflies in early June, followed by hatches of caddis and Pale Morning Dun  (PMD) mayflies later in the month, any day can see strong hatches. 

Yellow Sally stoneflies, caddis, and PMDs can hatch at subsequent times as well. A variety of caddis species ranging in size from 10 to 20 live in the Ruby River and hatch throughout June, occurring at various times throughout the day. 

PMD hatches typically begin mid-morning and last for several hours. Insects range in sizes from 12 to 18, with most being size 16. As a mayfly, it is important to understand trout may feed on emerging PMDs and not exclusively on fully hatched adults. 

Ruby River fly box for June

PMD dry flies size 14 to 18

PMD emergers size 16

PMD nymphs size 16

Caddis pupae size 12 to 16

Caddis CDC emergers size 12 to 16

Caddis dry flies with dark grey, black or brown bodies in size 12 to 16; 

Stonefly nymphs in brown and black in sizes 6 through 10

Yellow Sally stonefly dry flies in sizes 10 and 12

Sculpin patterns in sizes 2 to 6

Streamers in black or brown in sizes 2 to 6