Idaho’s Silver Creek

Woolly Worms and Renegades. Learning to fly fish in southern Idaho in the 60s and early 70s, these were about the only flies my fishing mentors bothered to show me. But they served me well–fishing small mountain streams and paddling around the high desert reservoirs in a primitive canvas float tube, these patterns caught fish. And my first paying job was tying Woolly Worms – at 15 cents apiece – for a local gun shop.

But then a teenage friend offered to show me a new spot–different, he said, than the places we had fished together before. We drove north through the sagebrush and lava outcrops and then climbed and dropped off the north side of Timmerman Hill. After several unmarked turns on gravel roads, we followed the contour of a low bluff that gave us a view of a stream winding through willows across the valley below. We climbed the stile over the fence and I approached the banks of Silver Creek for the first time. Staring into those crystal clear currents was like looking through a porthole into another world.

I spent hundreds of days in that world in the next few years, discovering fishing challenges around every bend of the creek. My dogeared copy of Selective Trout became my bible, and my Volkswagen Beetle knew the route to Silver Creek by heart. At first, the fish ignored my crude flies and clumsy technique. Reduced to utter frustration or tears, I laid my rod down in the grass, and I watched. I taught myself about the myriad of insects on the water, I learned to spot and stalk individual fish, I learned how to cast accurately, I became a skilled fly tier. But most of all, those hours spent sitting on the banks of Silver Creek taught me to really see.

Local geography

Springing out of the high desert country of southern Idaho, Silver Creek’s setting seems unlikely for one of the world’s best trout streams. The stream’s immediate source is an underground aquifer that lies east of the Big Wood River in the “Bellevue Triangle”, an area roughly 30 miles southeast of Sun Valley. Numerous small spring creek tributaries combine to form the best-known stretches of Silver Creek: from the Nature Conservancy Preserve, through the Purdy Ranch, past the little town of Picabo, and down to its confluence with the Little Wood River.

Silver Creek is a classic spring creek environment. Relatively constant flows and water temperatures, combined with the alkaline water chemistry, result in a very stable environment for aquatic plants and insects. In turn, these plants and insects support one of the richest populations of rainbow and brown trout in the country, estimated at over 5100 fish per mile. But there is more here than a trout fishery: The spring creek system also supports a diverse population of other plants, birds, and other wildlife.

The Nature Conservancy Preserve

Public access to a large reach of Silver Creek and its proximity to the resort area at Sun Valley have contributed to its fame as a fishery. These two factors are tied together in a convoluted history that starts in the 1930s with the development of Sun Valley Resort near Ketchum by Averill Harriman, chairman of Union Pacific. After the ski area was built in 1936, Steve Hannagan, head of public relations for the resort, invited a number of celebrities to Sun Valley to promote the area. For the history of Silver Creek, the most important invitation was one to Ernest Hemingway, who came to the resort in the fall of 1939. Though not much interested in trout fishing, Hemingway was an avid hunter, and he hunted waterfowl on a Silver Creek property owned by Sun Valley on his fall visits to the area, often accompanied by his son Jack.

In 1964, Bill Janss purchased the Sun Valley properties from Union Pacific. In 1975, Janss announced that he planned to sell his Sun Valley holdings, including the parcel on Silver Creek, where the public had been allowed access. The fishing community recognized that even if this land were not developed, there was a good chance that they would lose access to the Silver Creek fishery. It was Jack Hemingway, now a Wood River valley resident and commissioner for the Idaho Dept. of Fish & Game, who contacted the Nature Conservancy as a possible buyer. In the following year, the Conservancy purchased 479 acres from the Sun Valley Corporation, and the Silver Creek Preserve was born. Public access was preserved, and fishing is allowed on a fly fishing only, catch-and-release basis.

Additional parcels along Stalker Creek, one of the main tributaries on the upper creek, were purchased in 1980, 1994 and 1997, employing a standard strategy in the evolution of the Preserve–to retain some of the property from new acquisitions and to sell off portions with the protection of easements. In addition to the preserve itself (now 883 acres in size), conservation easements donated to the Conservancy now protect about 9100 acres along the stream.

The Rest of the Creek

Because of the ease of access, the Conservancy water is the best known to anglers, but there are miles of spring creek habitat and excellent fishing downstream. The Kilpatrick bridge marks the eastern boundary of the Preserve and the upstream boundary of the Purdy Ranch. Access to the Purdy Ranch water can be gained by one of two ways: paying a yearly trespass fee or floating this stretch of the creek in a belly boat (fishing from boats or canoes is not allowed). It is possible to float through the entire property, but many anglers launch at the Kilpatrick Bridge and fish the long “pond” section downstream and then kick back up to the bridge at the end of the day.

There is some additional public access on the lower creek below the Purdy property, including a spot at the Highway 20 crossing and at the Point of Rocks state access farther downstream. The water in this section flows through hay pasture with some willow cover along the banks. While the hatches are not as consistent and the fish not as numerous, some of the biggest fish in Silver Creek inhabit these lower reaches.

The fishing on Silver Creek

In the jargon of fly fishing, spring creek fishing is said to be “technical”: it requires a careful approach, light tackle, fine leaders, and accurate presentations of small, imitative flies. By anyone’s account, the fishing on Silver Creek is as technical as it 

gets. The normal spring creek challenges are there – clear water and slow currents that allow the fish a careful inspection of the fly, heavy hatches of insects that allow the fish to become selective to a single type of food. In addition to the natural challenges, constant fishing pressure (on the Preserve water in particular) has trained the fish to recognize the presence of human predators.

Fishing strategy on Silver Creek is defined by seasonal hatch activity. Midges and Baetis mayflies are on the water in the early spring, but anglers should note that the water above Highway 20 (the Conservancy water and the Purdy Ranch) is closed to fishing until Memorial Day. There is a winter “whitefish” season on the lower creek that allows catch-and-release fishing for trout from December through February.

The Brown Drakes are the first major hatch of the summer season. Like the salmonfly hatch on Montana’s Madison or Big Hole, traveling anglers often find this hatch to be a moving target, as the peak of the hatch lasts only a few days and weather conditions can move the best fishing earlier or later in the season. On the other hand, this evening hatch and spinner fall brings the biggest fish in the water around Point of Rocks to the surface, and an angler that pegs this hatch once will return in early June again and again, hoping to cast to that many big heads in the failing light.

The Pale Morning Dun (“PMD”) hatch is actually a complex of at least two species of insects and lasts through most of the summer. Relatively large and light colored, the naturals and artificials are easy to see, and this makes it a popular hatch, even among older anglers.

Spinner falls of tiny Trico mayflies provide excellent, but very challenging, morning fishing from July into early September. Fishing imitations of terrestrials can be effective during the same period, especially when there is a breeze to ruffle the water’s surface. Ants and beetles can be effective anywhere, but much of the best hopper fishing is in the lower reaches of the creek.

Although Callibaetis mayflies are common on stillwaters and the pond sections of most spring creeks, they are an important hatch on Silver Creek itself, especially in the lower end of the Conservancy water and the Purdy Ranch “pond”, as well as on Sullivan Lake, a spring pond on the Preserve.

Management Challenges on Silver Creek

Easy access to one of the premier trout fisheries has brought challenges to the managers of the Silver Creek Preserve. As on most well-known streams, increasing fishing pressure has been an issue. The Preserve saw about 1000 visitors in its first year, but that number has grown to a long term average of about 7700 visitors each year. After a spike in visitation levels in 1995-96-97 (when the Preserve saw over 10,000 visitors a year), the public was informed that a user fee program was being considered, and visitors responded with larger donations to the Preserve.

“Even though visitor donations and merchandise sales make up less than 20% of the Preserve’s annual budget, our goal is to increase visitors’ signups for Nature Conservancy membership to 50 percent and to collect at least a $5 donation per visitor, “ says Mike Stevens, the Conservancy’s Silver Creek area manager.

Although the Preserve water can be very crowded in the prime summer season, the Conservancy has no plan to institute rod limits. “We don’t want to spend valuable time policing the preserve or enforcing regulations,” says Stevens. “We’re stewards of a wonderful fishery, but that is not our total mission. We’re managing this as an ecosystem, not as a fishing club.”

A Silver Creek issue that created recent controversy was the announcement of plans to build three cabins on the Purdy Ranch just downstream from the Preserve. In 1995, the Purdy family donated easements to the Nature Conservancy on 3460 acres of their property, retaining development rights for 4 new homesites but giving up the option to subdivide. While most conservation easements include provisions for building or development rights, some in the angling community objected to the commercial nature of the development. An argument in favor of the development was that the cabins would be built on the site of a former feedlot, which would be moved away from the creek. To date, one of these sites has been developed, and although anglers floating through the Purdy property will see a structure close to the creek, Mike Stevens points out that the development has removed the feedlot and clustered development in one area.

In response to a small fish kill near Point of Rocks during a period of low flows in 1992, the Conservancy, area water users, and public agencies funded a study of the Silver Creek aquifer to gather existing water records and identify water use trends. Recently completed, the study maps the flow of water from the mountains north of Sun Valley and through the Silver Creek aquifer.

One interesting discovery is that a large proportion of the water that flows in Silver Creek today comes from irrigation recharges, both groundwater returns from diversions from the Big Wood River, as well as surface returns into the creek itself. Mike Stevens explains that when wetlands were drained and converted to pasture or grain fields, the nature of the Silver Creek system changed from a dispersed system of wetlands to one that pulls more water out of the Big Wood and recharges it into the aquifer. Because of this, the flows in the main channel of Silver Creek are higher now than they would have been earlier in its history.

The aquifer study also developed a hydrologic budget for the system and a mathematical model that will help predict the consequences of changes in water use patterns, such as changes in irrigation practices or the conversion of agricultural land into a residential development. This model will help direct future management decisions in the entire watershed.

Every angler has a piece of water that feels like home. Even though I moved away from Silver Creek, I have spent most of my life using the lessons I learned there, guiding and teaching first in Oregon and California, and now on the spring creeks of the Yellowstone and Gallatin valleys of Montana. But Silver Creek, winding through the sage at the foot of the Picabo Hills, will always be home to me.