Missoula Montana Fly Fishing Report- Rock Creek and Salmonflies 2/20/23



Rock Creek is a 50-mile-long tributary of the Clark Fork River located near Missoula, Montana. It is known for its excellent fly fishing opportunities, including the annual salmon fly hatch. Other great hatches include the green drakes, spruce moths and golden stonefly.

The salmon fly hatch on Rock Creek typically occurs in late May to early June, and it is a highly anticipated event for fly fishermen in the area. During the hatch, the river becomes filled with adult salmonflies, which are large, winged insects that are highly prized by trout as a food source. Anglers use large, dry flies that imitate the salmonfly to entice the fish to strike.


A brief summary of the life cycle of the salmon fly (pteronarcys californica):

Pteronarcys californica, also known as the giant salmonfly, is a species of insect that belongs to the order Plecoptera. This species is found in streams and rivers throughout western North America and has a unique life cycle that is adapted to its aquatic habitat.

The life cycle of Pteronarcys californica can be divided into three main stages: the egg stage, the larval stage, and the adult stage.

Egg Stage: The life cycle begins when adult giant salmonflies mate and lay their eggs on the bottom of streams or rivers. The eggs are usually laid in clusters and can take up to two months to hatch, depending on water temperature.

Larval Stage: The larvae of Pteronarcys californica are aquatic and spend most of their time on the bottom of streams and rivers. The larvae have a flattened, oval-shaped body and are covered with long hairs. They have six legs and two antennae, which they use to detect food and other environmental cues.

The larval stage of Pteronarcys californica can last for up to three years, depending on the temperature and quality of the water. During this stage, the larvae molt several times and grow larger. They feed on algae, aquatic plants, and other small organisms found on the bottom of streams and rivers. They can be quite ferocious when it comes to eating other nymphs.

Adult Stage: Once the larvae reach maturity, they leave the water and emerge as winged adults. This process occurs at night and generally takes an hour or more. The adult giant salmonflies have a distinctive appearance, with long, orange/brown bodies and wings that can measure up to three inches in length.


The adult stage of Pteronarcys californica lasts for only a few weeks, during which time the insects mate and lay their eggs. The adult giant salmonflies do not feed during this stage and usually die soon after mating. The good news about Rock Creek is that it has a number of other hatches that overlap the salmon fly hatch, providing excellent fly fishing even after the fish have stopped eating the salmon flies.

The salmon fly hatch on Rock Creek is one of the most important hatches of the year, and it draws anglers from all over the U.S. Because of proper permitting, crowding is rarely an issue. That said, it is still important to be courteous and respectful of other anglers (espaecially the wade anglers).

Overall, Rock Creek is a beautiful and productive fishery that is highly valued by anglers in the Missoula area and beyond. The annual salmon fly hatch is a highlight of the fishing season and a must-see event for anyone who loves fly fishing in Montana. Our schedule is full for the 2023 calendar year, but contact us for 2024 dates. This is a must-do float for anglers of any skill level.