Hooking into a smallmouth bass in Arrowrock Reservoir shouldn't surprise anglers.
Smallmouth bass are in the Anderson Ranch, Arrowrock and Lucky Peak system.
OK, I got excited about the hefty bass I caught in the reservoir this spring. It was pretty darn fat.
The cool thing about writing a column about it a couple of weeks ago was the feedback I got from readers.
The official scoop on smallmouth bass and Arrowrock Reservoir came from Herb Pollard, a retired fisheries biologist from the Idaho Department of Fish and Game.
"The smallmouth bass you caught in Arrowrock Reservoir probably originated in Anderson Ranch Reservoir," Pollard said.
He should know. His first job with the Idaho Department of Fish and Game in 1969 was as a research project biologist working on northern pikeminnow control and kokanee introduction at Anderson Ranch.
For all you newbies, Anderson Ranch is on the South Fork of the Boise River. Its waters flow down the South Fork, through Arrowrock and Lucky Peak reservoirs then into the Boise River through the valley.
The smallmouths were introduced and stocked in Anderson Ranch from 1972 to 1975. Thousands were caught by hook and line from Brownlee Reservoir on the Idaho-Oregon border and transported to Anderson Ranch. Explorer Scouts helped Fish and Game with the project.
"The smallmouth bass immediately did well and reduced the northern pikeminnow and redside shiner population," Pollard said.
But the growing season for smallmouth bass in Anderson Ranch, which is at 4,200 feet in elevation, is fairly short. They need a longer, warmer season.
"The smallmouth bass ate most of their food supply, so there are not many large ones," Pollard said. "But a 10-inch smallmouth bass is better than a 16-inch northern pikeminnow."
(Anglers do not consider pikeminnow a game fish.)
OK, back to the present. A few smallmouths are always washing out of Anderson Ranch and into the South Fork during the spring.
They don't stay in the South Fork because the water is too cold and they end up in Arrowrock. The water level fluctuates too much at Arrowrock, and that's not conducive to bass reproduction.
About the time the water warms up enough for smallmouth bass to spawn in Arrowrock, the reservoir level starts dropping for irrigation withdrawals and the bass nests are left dried out on the shoreline.
There are a few smallmouth bass that live in Arrowrock, chowing down on the shiners and northern pikeminnows.
However, Pollard said, smallmouth bass do better in Lucky Peak Reservoir because the water levels are more stable in the early summer.
Here are some other historical tidbits from Pollard:
In 1887, William Ridenbaugh (as in the builder of the Ridenbaugh Canal in Boise) planted largemouth bass in his mill pond near where the old railroad bridge crosses the Boise River upstream from the Fairview Avenue bridge.
Ridenbaugh also released largemouths in the Boise River in 1892.
The same year, the U.S. Fish Commission brought more largemouth bass, carp and other fish to the Boise and Snake rivers.
Ridenbaugh is credited with the original stocking of bass, crappies and perch that we catch in several southwest Idaho waters.
Smallmouth bass came much later. The first notable populations were in the Snake and Clearwater rivers in the 1940s or 1950s.
There were no smallmouths in the Boise River upstream from Boise or in the Snake upstream from Swan Falls Dam until Idaho Fish and Game stocked them in the 1970s.
In the 1980s, Fish and Game stocked smallmouth bass in the Snake River as far upstream as Milner Reservoir, where they are doing well.
Thanks Herb. Appreciate the smallmouth history lesson.