A 110-mile trip that takes 250 river miles
Draw a line from the forks west of Hartville in Wright County to the Missouri River at Gasconade and it measures about 110 miles, MDC says; the river needs more than 250 to cover it. MDC's 2001 watershed inventory gives 271 miles from headwaters to mouth, Wikipedia rounds to about 280, and all three sources call it the longest river that stays entirely within Missouri. The bends are the story. At the Narrows, near mile 103 of the MDC river log, the neck of land is 0.2 mile across and the river takes 6.5 miles to get around it, and near Waynesville you can float 15 miles and end up two miles overland from your car.
There are no dams and no trout on the main stem. What it has is 76 springs, including Boiling Spring below the Big Piney mouth at 42 million gallons a day, and about 33 miles of losing stream in the middle river where water sinks into the dolomite.
Riddle Bridge to the Route D bridge: the 15-inch water
MDC's smallmouth special management area runs from Highway Y in Pulaski County, the end of the road at Riddle Bridge Access north of St. Robert, to the Highway D bridge at Jerome in Phelps County. Inside it, smallmouth must be 15 inches and only one of your six black bass may be a smallmouth. By the MDC mile log that is roughly mile 129.9 to mile 150, about 20 river miles. It began in 1994 as a research area with an 18-inch limit. There is no special goggle-eye rule on the main stem, so the statewide 15 a day and 7-inch minimum apply, but two tributaries that join nearby carry their own: the Big Piney from Slabtown Access and the Osage Fork from Skyline Drive are both one-smallmouth, 15-inch water, and the Big Piney below Highway 17 and the Osage Fork hold goggle-eye to 8 inches.
Everywhere on the river, black bass taken from the stream must go back from March 1 through May 22; the 2026-27 harvest season runs May 23 to February 28 with six a day and a 12-inch minimum outside the special area. You only need a standard fishing permit here.
Hazelgreen, the Narrows and the floats above Riddle
The Osage Fork comes in at mile 74.6, and Hazelgreen Access sits under the old Route 66 and I-44 bridges just below. Gasconade Hills Resort near Richland runs a 4-mile float to Hazelgreen, two to four hours, and a 6-mile run from Barlow Ford, with longer trips from Black Ford and Adams Ford March to October. Mitschele Access is at the Highway 7 bridge, mile 92.5. Four miles below it is the Rochester Road low-water bridge, which the MDC log says to portage at any level. Schlicht Springs is at 106.1, the Roubidoux and the Highway 17 gravel bar at 116.3, then about 14 miles of bluff water to Riddle Bridge, where Portuguese Point stands roughly 250 feet above the bend.
Above Competition, the old MDC float guide says, the river is a spring or high-water float unless you are willing to walk the riffles and fish the pools. The upper legs from Odin and Camp Branch on the Woods Fork run 4 to 12 miles between access points, and Odin is wade-only.
Jerome, where the special water and the gauge meet
USGS 06933500 sits at Jerome, the downstream end of the special area, just above where the Little Piney enters. MDC opened a new access off the Route D bridge with a concrete ramp and bank access to both streams, and it came through the November 2024 flood fine. Boiling Spring Campground at Dixon will run you 14 miles from Riddle Bridge by appointment. Below Jerome the log continues to Bell Chute near Vienna, Paydown, Rollins Ferry at Highway 89 and Pointers Creek.
The long-term USGS monthly means at Jerome run from about 1,260 cfs in September to 4,783 in April. In late September 2026 it was far below that, 426 to 618 cfs. No outfitter publishes a wading range for this gauge, and Gasconade Hills only warns that levels change fast with rain. The 400 to 1,600 cfs band on this page is built from that record: the bottom is the late-summer 2026 base flow, the top is the July mean, the kind of summer and fall water when smallmouth are spread through the riffles. Well above the spring means, stay home.
Winter in the boulder pools, May on the gravel
MDC's own prospect report says the special area fishes well all year and especially in winter, when smallmouth drop into the deepest pools with big rocks and downed timber and gather wherever a spring warms the water; they do not travel far to find those pools. Males move to shallow gravel once water reaches the low 60s, spawning peaks in May, and most legal fish are kept in June. As water cools in September, fish boulders and logs in two to four feet of water.
The honest news is mixed. MDC's fall 2025 samples showed smallmouth in the special area still declining in size and number, which it ties to repeated flooding since 2011, though 11 to 15 inch fish remain more common there than up or downstream and largemouth over 18 inches are still common. MDC suggests larger crayfish imitations and shallow crankbaits below riffles; its 2016 Conservationist trip caught fish on a 3-inch brown twin-tail grub and a Rebel craw. Fly anglers do well with crayfish patterns, Clousers and bass bugs, and spotted bass up to 15 inches are fair game to keep.