Daryl Dispensire knows the Mississippi River is northern Illinois' best bass fishery. Photo by Ted Peck

By mid-April, largemouth bass action on upstate Illinois waters will really be heating up. Those who fish bucketmouths in the northern third of our state are on the cusp when this game fish is touted by most outdoors writers. Regional articles must consider closed seasons in states just north of us. General state articles tend to be heavily slanted toward downstate waters where there isn't much opportunity to explore a pattern that happens just after ice-out.

We're going to look at some of northern Illinois' top bass waters in this article. But first, a quick look at an effective bass-catching pattern that only applies to upstate Illinois lakes over the next several weeks.

If you're itching to tangle with Ol' Mossback when she is still tinged with a touch of frost, sharpen the hooks on lipless vibrating crankbaits, spinnerbaits and suspending stickbaits. Then check your surface temperature gauge for accuracy. Within a few days either side of April 20, it will be time to bust a move on bucketmouths. Exactly why largemouths go on a feeding rip when water temperatures warm to 43 degrees is something I haven't figured out yet. But believe me, they do. This magic number occurs in the far north end of most lakes first, especially if there is a dark bottom that accelerates the warming trend.

When waters warm to 48 degrees, it's time to put away the Rat-L-Traps and spinnerbaits, and to try an almost deadstick-like approach with suspending stickbaits -- or move to another part of the lake where water is in that magic 43- to 48-degree window. Bass in early spring tend to congregate around the warmest water. You may find this hot pattern effective on only a couple hundred yards of shoreline on a 500-acre lake.

In perfecting the nuances of this pattern over the past 20 years or so I have discovered the largemouths show a real affinity for orange/red crawdad-patterned lures. Slow-rolling seems to work best with spinnerbaits. When you're tossing the Rat-L-Trap, bring it back with a steady medium to almost fast retrieve. This is a striking rather than a feeding presentation in waters less than 6 feet deep. When ice leaves the lake, bass seek the warmest water. Predatory instincts seem to take precedence over caution in that brief window between 43 to 48 degrees. At 48 degrees, it's almost like their brains thaw out, sending the fish skulking toward deeper water and heavy cover where they'll grudgingly take a jig-and-pig or similar presentation until waters warm beyond 55 degrees. That's when most bass anglers start getting serious about chasing Illinois' most popular game fish.

Here are some upstate hotspots to try these theories right now during the magic time of spring.

MISSISSIPPI RIVER
The northernmost pools of Old Man River -- pools 12, 13 and 14 -- offer over 60,000 acres of potential bass-holding water that is arguably the best public bassin' in northern Illinois.

Largemouths in the Mississippi River behave differently than their lake-dwelling brethren. The 43- to 48-degree pattern mentioned earlier applies to riverine bass, too, but it doesn't last as long. Plastics like the Chompers Skirted Hula Grub or a tube jig are good weapons to have close at hand.

Right after the river level recedes after ice-out -- and before the cool, blue north sends its winter runoff flushing downstream -- look for bass in shallow sloughs off the main river channel and backwaters where you found them at late ice.

In the Mississippi the general spring pattern of fish congregating over a reasonably tight area persists throughout the year. After waters warm, this tendency is related to forage base movement more than water temperature. A forage base movement is driven primarily by river level and current velocity.