Each state's Department of Natural Resources and fishing-license outlets have maps readily available that include every trout stream in the state. Choosing a stream to explore is easy; all streams in the Driftless Area have potential. I'm still finding productive creeks I've never fished before. [Ross Mueller is the author of two guidebooks for the area: Upper Midwest Flies That Catch Trout (1996, R Mueller Publications, ISBN 0964804700, $14.95) and Fly Fishing Midwestern Spring Creeks (2000, Amherst Press, ISBN 0964804719, $15.95). These books are excellent resources for a trip to Driftless Area streams. The Editor.]

Ask permission before crossing private property.

The lower, marginal reaches of trout water are especially good choices. This is larger water, having received more tributaries, with less current due to less gradient. Due to the slower current and greater width, these waters are warmer and tend to support more forage fish, which in turn attract and support large brown trout. Furthermore, many of these reaches have not received a significant amount of habitat work by Department of Natural Resources crews and are not as publicized. Fewer streamside easements have been obtained--thus the lower regions are private--and the trout are less disturbed. Because much of this water flows through private land, you need fishing permission from the landowners. I've found that most are willing to provide it to courteous fly fishers.

Spotting trout. Plan to explore on a sunny day with clear water. Wear polarized sunglasses and look closely for trout. If after a stealthy approach you do not see any fish, kick beneath undercut banks or logs to flush them and mark the spot for a return visit. Trout may be absent for fairly long reaches of river; then one area may hold a pod of several fish.

Under bright lighting conditions, seeing into the deep pools is easy and you will almost certainly see fish. Learn to recognize rough fish, so the large suckers, carp, and red horse do not mislead you. If a fish has a forked tail, it is not a trout. Brown trout have square tails that often appear dark at the tip with a lighter band in front. Rough fish move their tails with a looser "wiggle" or sway than trout. Suckers can show a mottled appearance, and often the leading edge of the pectoral fin is light and contrasts sharply with the body color. At times, you can spot the white mouth of a brown trout.

Small creeks in the Driftless Area can hold large trout.

Finding trout. Learn to recognize the characteristics of water that holds trout, usually a riffle with a drop-off of good depth and often in the vicinity of a submerged log or large bankside tree. Cobble bottoms with some larger stones are good; silted areas are poor. Look for a nearby "feeding flat." Make note of small cold feeders and wooded areas, especially those with riffles. These areas will be cool in mid and late summer and large trout may congregate in them, making the area worthy of a return visit.

Don't overlook the upper stream reaches. Some creeks that are just a trickle under the bridge may have some impressive pools farther upstream. Because these headwater creeks receive less fishing pressure, your chances of encountering large brook or brown trout are excellent, especially in September as browns and brookies migrate upstream in preparation for spawning.