Saint Mary Lake Montana

Fishing Saint Mary Lake in Montana

Saint Mary Lake is a large and windy waterbody located in the eastern section of Glacier National Park. Stretching an impressive ten miles this lake is surrounded by natural beauty. It is seen and even photographed by many people traveling the popular Going-to-the-Sun Road but it gets very little pressure of any kind.

Anglers are a rare site on Saint Mary Lake and even recreational boating is limited. Saint Mary Lake does get more attention than the much smaller Lost Lake located just across the road however.

The outflow of Saint Mary Lake forms a moving waterway that would be accurately described as a stream or even river in most parts of the world. That outflow passes under the road and past a campground before emptying into Lower Saint Mary Lake. The water in the outflow is crystal clear and it holds a decent number of fish.

Fish species in Saint Mary Lake in Montana

Saint Mary Lake is home to a population of lake trout. They are joined by rainbow trout and cuthroat trout. These fish are often found in areas that cannot be fished from shore. Yet the remoteness of the area, near-constant winds and dearth of boat launches mean few watercraft use Saint Mary Lake, especially for fishing.

mountain whitefish from st mary lakeAn average Saint Mary Lake mountain whitefish

The most common species in Saint Mary Lake is undoubtedly the whitefish. While the whitefish has been written off or even derided by a number of western anglers this species actually provides good sport. It is an eager feeder that can put up a good fight for its size.

Fishing in Saint Mary Lake

Before I tell you about fishing here, I want to let you know that I may earn commission when you make purchases through links on this page. This commission helps support my website, but it does not influence what I write. I only recommend products that I have found to be effective.

The lake trout in Saint Mary Lake hold deep for most of the year. They are thus best targeted by artificial lures like spoons fished deep. In Saint Mary it seems that most of the rainbow trout also follow the deep water pattern.

outflow of saint mary lakeThe outflow of Saint Mary Lake

The whitefish are much more accessible to anyone fishing from shore. They can be caught all around the lake. But most of the shore fishing done at Saint Mary Lake happens around the outlet. There are good reasons for that. One is surely the nearby road and campground. But this free flowing section is also one of the best areas for catching mountain whitefish.

Catching mountain whitefish is much like catching trout. If you present a replica of a small aquatic insect to them in a way that looks natural you have a good chance at eliciting a strike. I’ve seen sporadic stonefly hatches around the outflow but truthfully anything that looks like a nymph generally would work in most cases. The most difficult thing about catching whitefish besides making a natural presentation may be setting the hook. Mountain whitefish have small mouths tucked under their snouts.

Saint Mary Lake stoneflyA size 6 adult stonefly along the St Mary outflow

I’ve had good success in the Saint Mary outflow using flies and small soft plastics on light lines on multiple occasions. Using a clear two to four pound test leader I drifted flies like size 16 Red San Juan Worms and small soft plastics like Soft Micro Nymphs near the bottom.

Using floats like the Trout Magnet EZ Floats I was able to detect the slightest bites and catch a decent number of fish both above and below the bridge. It is just like drift fishing for trout and steelhead.

Saint Mary Lake fishing regulations

Saint Mary Lake falls under the general fishing regulations that apply to Glacier National Park as a whole. That means Saint Mary Lake is open to fishing all year. Fishing must be done with artificial lures or flies. The use of any kind of lead is prohibited. Felt soled waders are also prohibited.

You can keep some fish from St. Mary Lake if you’d like. The maximum limit on cutthroat is two. The limit on mountain whitefish is two. The limit on Lake Trout is five. You can keep 2 burbot. You can also keep a northern pike. Note that you cannot keep or posses more than five fish in total.

The outflow of Saint Mary Lake is open for fishing from the third Saturday in May until November 30 each year. Native fish must be released.

Ice fishing is permitted on Saint Mary Lake but power augers are prohibited anywhere in the park. With the wind and sustained low temperatures common to Saint Mary Lake, it could be tough to drill a hole by hand.

Mary Lake is open to boating from June 1 until the last Friday of September. Boats must be inspected and permitted by park staff before they can be used. Inspections can be done at the St Mary Visitor Center near the lake between 7:00 am and 4:30 pm. Boat trailers cannot enter any waters in the park unless they have been quarantined for 30 days. Non-motorized boats must be launched by hand.

To the best of my knowledge, this is accurate as of the time of writing. Of course regulations are subject to change at any time. For current regulations be sure to check the Glacier National Park website.

Saint Mary Lake fishing at a glance

Fish species present: Mountain whitefish, lake trout, cutthroat trout, rainbow trout
Closest tackle shops: St Mary Grocery
Recommend line: 2-4 lb monofilament / 3-4x leader
Recommended lures: Micro Nymphs, Custom Stonefly Nymphs, Little Cleo spoons
Recommended flies: San Juan Worm, squirmy worm, Kaufmann's Stonefly Nymph
Nearby hotels: Super 8 Cut Bank

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