Smallmouth bass

Identification and biology

The smallmouth's upper jaw ends at about the back of the eye, never past it, and its two dorsal fins are joined with only a shallow notch. Instead of a horizontal stripe it carries faint vertical bars on greenish-brown sides; South Carolina DNR adds three dark streaks radiating back from the eye, and an eye that is usually red. Missouri gives 10 to 20 inches as the common length and about 22 inches and 6 pounds as a top, while Michigan DNR says most fish anglers see are 8 to 15 inches and under three pounds, maturing at three or four and occasionally living 10 to 12 years. Adults eat fish, crayfish and large aquatic insects, and Missouri notes their habit of trailing a rooting sucker or turtle to grab whatever it flushes.

Where to look

Texas Parks and Wildlife describes the preferred habitat as large clear lakes over 100 acres and 30 feet deep, and cool clear streams with gravel. In rivers they hold near riffles but out of the main push of current, behind boulders, logs and undercut banks. Spawning starts when the water nears or passes 60°F, from April into June or July in Missouri with the peak in May, and the male builds a gravel nest in quiet water near shore or below an obstruction that breaks the current. Iowa DNR's river advice follows the seasons: in July and August the small fish work the riffles while the larger bass sit on structure reaching into deep holes; in spring and fall the bigger fish come up to shallow cover.

The mistakes that cost fish

Heavy, visible line: smallmouth feed by sight, and Iowa DNR recommends light line with a fluorocarbon leader for that reason. Ignoring water clarity after rain: Iowa notes river clarity can crash quickly, and suggests spinnerbaits, rattling crankbaits and dark or chartreuse colors when visibility drops to about six inches. And fishing the summer riffles for big fish, when Iowa's observation is that the larger bass have moved to the deeper structure.

Tackle setups

Playbook by water temperature

The legal season is a separate question

Month by month

Best waters for smallmouth bass

324 waters we report on where this species is one of the main fish, each with a daily report.

Common questions