Brown trout numbers in the Waterloo section have doubled, and the rainbow population spiked more than 1,000 percent. (Ben Pierce photo)
March 01, 2022
By Ben Pierce
Near Waterloo, not far from the east bank of Montana’s Jefferson River , cold springs bubble from the rich agricultural land at the foot of the Tobacco Root Mountains. The springs create a series of ponds and slow water historically called Parson’s Slough. The slough is lined with willows and cottonwood trees, and runs a short distance to its confluence with the Jefferson.
In the past, the importance of Parson’s Slough was overlooked. Sure, the creek provided a source of cold water to a river that suffered from high temperatures and low flows. And yes, a few rainbow and brown trout made their way upstream each year to spawn in the clear water. But the slough was choked with silt and lacked much in the way of flow. The spawning habitat was marginal and even the most intrepid anglers didn’t give the slough a second thought. But Montana Fish, Wildlife & Parks, led by fisheries biologist Ron Spoon saw a future for the slough that could impact the entire Jefferson River fishery.
In 2014, SSRM created another mile of spring creek by narrowing the slough channel and increasing flow. That fall, there were 40 new brown trout redds. (Ben Pierce photo) That new future began in 2004 when a change in property ownership opened the door for an ambitious habitat improvement project with the goal of creating spawning and rearing areas to boost the Jefferson’s depleted trout populations.
“Typical of a lot of spring creeks that have had livestock use, Parson’s Slough had become wide and shallow and muddy,” Spoon said. “The ducks liked it, but there was very little fish use.”
The Parson’s Slough project was separated into two parts. On the upper section, the landowner improved habitat to create holding water for adult trout. Closer to the Jefferson, FWP partnered with TU and Golden Sunlight Mine and used excavators to narrow the slough channel and create areas where fish could build redds.
The results were swift and significant. Rainbow trout abundance in the 3.5-mile Waterloo section of the Jefferson in 2004 was approximately 200 fish. Today, there are more than 2,000 rainbow trout between 8 and 12 inches. Brown trout abundance in the Waterloo stretch has more than doubled in the Jefferson over the same period.
“The stream work changed the grade control so it approached the river with a greater flow and made it more of a spring creek rather than a slough,” Spoon said. “Brown and rainbow trout spawning has been extensive.”
Seeing great potential in the fishery, Silver Star Resource Management (SSRM) purchased the Parson’s Slough property in 2012. Led by Bill Kemph, SSRM continued to develop the spring creek character of Parson’s Slough. With guidance from FWP, Kemph developed another mile of the creek upstream of the original habitat project. Brown trout established 40 redds in that new channel last fall. Sections of the original project have been reworked to further improve holding water for adult fish and to create rearing areas for juvenile fish.
Bill Kemph of Silver Star Resource Management helped turn a muddy slough into an important spawning tributary. (Ben Pierce photo) “They took it to another level,” Spoon said. “Most important in my view is that they continued the project upstream.”
Parson’s Slough now fishes like a spring creek, and it’s got the trout to prove it. PMD hatches offer spectacular fishing in the morning , and browns and rainbows rise eagerly to caddisflies in the afternoon. When the grasses turn golden in the late summer, the hopper fishing can be electric.
It’s quite a change from the mediocre midge hatches that once occurred on the muddy flats a stone’s throw from the Jefferson. And the benefits are being felt downstream.
“I was here in ’88 and you could walk across the Jefferson in knee boots and not get wet,” Kemph said. “From ’89 clear through the ’90s, we wouldn’t even come down here to fish.
“The Jefferson is a real fishery now,” Kemph said. “It is still a little bit of a cruel mistress, but on the days it is on you can really see some special fish. This project has helped the Jefferson immensely.”
Ben Pierce has had work published in numerous national and regional publications. Ben also produces short films for a variety of clients both nationally and internationally, via his production company Side Channel Productions.
