Spawning

• Spawn date—April through June

• Substrate size—1-in to 3-in and substrate must be stable to avoid shifting and damage to eggs.

• Water depth—1-ft to 2-ft

• Stream feature—More varied than for chinook. Not much spawning in main channel, and is primarily in small tributaries and side channels. Occurs in tail of pool, long runs, and in areas of spring upwelling.

• Velocity—Variable

• Water temperature—Optimum range is from 50°F to 60°F

• Good Example—Big Springs Creek (tributary to the Pahsimeroi River) near mouth of river. Also, a rare example within the 12-mile reach of the Salmon River near Challis, the graded sediment bars that form behind some of the barbs. Another rare example is the graded sediment at the downstream end of large sediment deposits.

Graded Sediment Bars Form Behind Barbs

Graded Sediment At Downstream End of Large Sediment Deposits

• Typical Conditions for 12-Mile Reach of the Salmon River Near Challis—Very gradual tail-out from pools with oversized materials and sediment choked.
  

• Locations of spawning.

Rearing Fry/Parr

• Time line—Emerge from gravel in June and July, depending on water temperatures. Rear in natal streams and the main river during their first summer. During the fall they begin migrating to the lower reaches of the main Salmon River for overwintering.

• Velocities—Reside in edges and pocket water of main channel flow (protected areas behind large boulders)

• Water temperatures—Optimum range is from 53.6°F to 64.4°F and the upper limit is 77°F for short time periods.

• Feeding—Feed on all types of available insects

• Predatory considerations—In the tributaries, otters and the kingfisher are primary terrestrial-based predators. Large fish such as the northern pikeminnow and bull trout are another primary predator for the fry/parr. Complex habitat such as debris piles and bank overhangs are important shelters from the predators. In the Salmon River, the herons, otters, and large fish are primary predators. Cover from these predators is similar to the previously described.

• Depth—Variable

• Stream feature—During the 1 to 3 years of juvenile freshwater residence the fry/parr seek cover in pocket water of the swift stream flow of the tributaries. After migrating to the Salmon River, the fry/parr shelter near the edge of the stream. During the winter, the fry/parr shelter in the interstitial spaces in the substrate of the channel bed (consequently, sediment free substrate is important).

• Good Examples—Hannah and Philips sloughs. Common examples within the 12-mile reach of the Salmon River near Challis, shallow pools (around 2-ft deep) with low velocities.

Shallow Pools With Low Velocities

Smolts

• Time line—After approximately one to three years of freshwater residence, the steelhead begins seaward migration during the late spring, generally coinciding with runoff.

• Velocities—Variable

• Water temperatures—Same as for fry

• Feeding—Feed on all available insects.

• Predatory considerations—Similar to fry/parr for the Salmon River-related predators.

• Depth—Variable

• Stream feature—Main channel free of obstructions.

Adults

• Time line—Adults migrate back into the Salmon River basin arriving in January or February after 2 or 3 years in the ocean.

• Velocities—Same as fry

• Water Temperature—Same as for fry

• Feeding—Feed on all available insects

• Predatory considerations—Same as chinook

• Depth—2-ft to 6-ft

• Stream feature—Hold in pool-like runs (less than 4-ft deep but generally more than 2-ft deep, with uniform flows across section).

• Good Examples—Pool-like runs.

Pool-Like Runs

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