The lowest reach on the South Fork is often referred to simply as “Section 5,” but local anglers usually call it by the names of the two public put-ins/takeouts: Lorenzo to Menan.
It flows from the Lorenzo boat ramp just west of the U.S. Highway 20 bridge over the river just north of Rigby, Idaho, to the takeout just above the river’s confluence with the fabled Henry’s Fork near the town of Menan.
Most anglers ignore this section of the river, but, like the Brown Town reach above it, the Lorenzo-to-Menan float can turn up some really big brown trout, particularly in mid-June and into July when the salmon flies start to emerge, and from July well into October, when the area is bustling with grasshoppers.
While rainbows, cutthroats and whitefish can still be found, warmer water temperatures are more conducive to browns. Like Brown Town, there are fewer fish in this reach, but the fish that are here are generally bigger.
Even though water temperatures are warmer in this section, the South Fork is still cooler than the Henry’s Fork near the confluence. That means some of the bigger browns and rainbows from the Henry’s Fork and even from the mainstem of the Snake River below the confluence will move into the South Fork later in the summer in search of cooler water.