In Montana, we are extremely fortunate to have an incredibly wide array of types of fisheries that range from technical tailwaters like the Missouri to brawling freestone rivers like the Yellowstone. In addition to larger fisheries Montana has some of the world's best spring creeks. These small streams originate in the middle of broad valleys when underground aquifers produce springs at the surface. The stable conditions and cold water produce the ideal habitat for aquatic insects which trout feed on. I guide on seven different spring creek systems across Southern Montana and McCoy Spring Creeks is my personal favorite. Even though it is a two hour drive from our base in Bozeman, I find myself scooping up as many rods as I can for our clients on these amazing creeks from April through October. The trout at the McCoy creeks are big and they love to eat dry flies. They also receive rest days each week and receive far less pressure than the larger spring creeks near Livingston which allow as many as 16 rods per day (McCoy's maxes out at 4). The creeks are home to brook, rainbow and brown trout. The average fish in the creeks runs from 14-18" with MUCH larger fish up to 28" in relatively good abundance. The hatches on McCoy spring creeks can be spectacular and bring up even the largest trout to the surface. Terrestrial fishing can also be superb. If you don't get enough of the two spring creeks on the property the spring fed ponds filled with large cruising trout provide plenty of sight casting to midging fish.
The habitat is a blend of large slow moving deep runs, shallow and wide flats and s-turn bends with beautiful undercuts. There are two spring creeks on the property that merge just near before it exits the ranch as well as two outstanding stillwater fisheries. We generally strip streamers early in the morning on the smaller creek which has less hatches and then work the larger creek that produces some of the world's best spring creek dry fly fishing. The creeks run through a broad meadow and sneaking up on runs on your hands and knees can often reduce the number of trout that you spook.
Some of the highest catch rates of the season occur in April and May when the weed beds are at a minimum and the fish are uneducated. This is a great time to strip small streamers for some of the monstrous browns that live under the undercut banks. Strong hatches of baetis mayflies also produce good dry fly fishing in the late afternoon and the ponds produce excellent midge hatches in the late morning. 30-60 fish days are not out of the question in April and May and you almost always get a few hookups on the fish over 20".
My absolute favorite time to fish the creeks is from mid June to mid July when the pale morning dun hatch occurs. This mid sized mayfly is like a drug to these trout and they simply cannot get enough. Spring creek trout are always spooky, but when the hatch is on you can afford to make a few mistakes and still get hook ups. During the peak of the hatch bugs are thick on the water and every run is filled with 10-40 trout ravenously gulping at the surface depending on the size of the hole. These heavy hatches interest even the large browns and will draw the big boys to the surface during the peak of the hatch. Last year I hosted Trout TV during the PMD hatch and the fishing was so good they broke up the footage into two shows with several fish over 20" caught on the dry to the net.
By late July the PMD hatch has ended and the trout shift their focus to terrestrials. Ants, beetles and hoppers run the show. The trout get spookier and the weeds begin to fill in making nymph fishing difficult. Catch rates go down but the quality of the fishing is superb and the hopper takes on these small spring creeks can stop your heart when a monster bow rushes 8 feet across skinny water to crush a fly.
Most of september is still terrestrial time with spooky trout sipping ants and beetles. As you move later into the fall the weeds begin to die back and the fall baetis can bring some great action. Cloudy days can be spectacular and the fishing pressure is even lower than normal. Some of the big browns become less wary prior to the spawn and will succumb to small streamers in late October.
Brian McGeehan is the owner and outfitter of Montana Angler Fly Fishing, based in Bozeman. He and his guides spend about 15-20 days guiding at McCoy spring creeks and Brian has also hosted two episodes of Trout TV at the Montana Property.