Photo: DawnBreaksOverMarblehead Opens in a new tab. · CC BY-SA 4.0 Opens in a new tab. · Historical South Branch photograph, not today's conditions. Cropped for display.
Fishable. Start with a quiet South Branch session.
Check your fishing spot before entering. Use the gauge’s water temperature when current, then measure your fishing spot. The station does not measure footing, clarity or every bend. As a conservative trout-care rule, stop at 70°F or warmer, or sooner if fish show stress.
Check first: South Branch flow, measured temperature and weather support planning. Footing, clarity, fish activity, crowding and temperature at the exact access are not measured.
Rating updatedRiver local time:
USGS shows 246 cfs. The flow has been stable over about 6 hours. USGS marks this reading provisional and may revise it. This is the clearest starting signal.
NWS air forecast near
Discharge
Latest reading: 248 cfs. Stable over about 6 hours. Chart covers Sep 11 through Sep 17; readings are provisional and may be revised.
Water temperature · °F
Latest reading: 59.2 °F. Falling over about 6 hours. Chart covers Sep 11 through Sep 17; readings are provisional and may be revised.
This is the gauge water temperature, not a reading at every reach or access. USGS readings are provisional and may be revised.
Mostly Clear
The National Weather Service forecast is temporarily unavailable.
Current U.S. Geological Survey gauge: South Branch Au Sable near Luzerne
Seasonal starting points, not a live hatch report. Match what you see on the water.
Start with your month's row, then match insect size, stage and feeding. These are seasonal options, not a live hatch report.
Photos show the named artificial pattern or disclosed family example. Brown Drake and Hex hatches need dedicated size-and-stage matches; the pictured sulphur, caddis and soft-hackle options are not exact Hex imitations. The Woolly Bugger photo is black; the BWO and Sulphur photos are dries, not emergers or spinners.
Watch the flow trend, recent water heat and forecast before committing to an evening session. Stable readings help planning, but only observed feeding tells you which presentation to use.
Pick a reachable seam and control the drift. Stable discharge does not confirm clear water or safe wading.
Avoid crossings. Stay on a legal bank when the depth, footing or exit is uncertain.
Approach quietly and protect shallow holding water. Low discharge does not prove low water temperature.
Read the current temperature and recent high, then check your fishing spot. As a conservative trout-care rule, stop at 70°F or warmer, or sooner if fish show stress.
These scores compare the risks of wading, bank fishing, and floating.
Only enter a visible protected edge after checking current, depth, footing, temperature and an easy exit. Avoid forced crossings.
Choose a legal bank with stable footing and casting room. Check temperature, weather and the rules for your side of Lower High Banks.
This report does not recommend floating this reach.
Plan a trout session through the Mason Tract near Roscommon and Grayling. Use the South Branch readings, choose a legal access, and match your fly to the feeding you see.
USGS 04135700 near Luzerne supplies flow, stage and measured water temperature. The fishing rating combines current readings, recent temperature history and weather. It does not measure fish activity, clarity or safe footing.
USGS shows 246 cfs. The flow has been stable over about 6 hours. USGS marks this reading provisional and may revise it. This is the clearest starting signal.
September–December: Small olives, nymphs and streamers are options as water cools.
USGS water temperature is about 59.5F, and the rolling 24-hour high did not trigger a heat caution. USGS marks the temperature data provisional and may revise it.
Leave for lightning, rapid rises, uncertain footing or posted restrictions. Stop trout fishing at 70°F or warmer, or sooner if fish show stress.
Bank / edge: Choose a legal bank with stable footing and casting room. Check temperature, weather and the rules for your side of Lower High Banks.
Use fresh South Branch readings and the trend. Seasonal flow history gives context, not a universal safe or productive cfs band.
Leave for lightning, rapid rises, uncertain footing or posted restrictions. Stop trout fishing at 70°F or warmer, or sooner if fish show stress.
Choose a mapped entry, identify the Lower High Banks rule zone, and watch one reachable lane before selecting a fly.
Return during a cooler or more workable window. Another river needs its own gauge, temperature, access and rule check.
When: Year-round fishing within exact-reach rules
Brown, brook and rainbow trout guide this plan. Match actual food and feeding, and stop when water heat makes trout handling inappropriate.
When: Separate report
This rating does not describe Mio tailwater conditions, lower-river migratory runs or reservoir boating.
Use the DNR pathway map and posted approaches. A mapped river landmark does not guarantee safe footing or permission to cross every bank.
Chase Bridge–Lower High Banks: year-round fishing, artificial flies only and no trout possession, except children under 12 may keep one trout measuring 8–12 inches. Lower High Banks–main river: year-round fishing, artificial flies only. Brook and brown trout possession runs from the last Saturday in April through September 30. Rainbow possession is year-round. Daily limit: two trout, no more than one 18 inches or longer. Minimums: brook/rainbow 10 inches. Brown 18 inches. No bait or scented material in the water or on shore in these gear-restricted sections. Check current DNR orders and posted boundaries before fishing.
| River section and season | Fishing rules |
|---|---|
| Chase Bridge–Lower High Banks | Chase Bridge–Lower High Banks: year-round fishing, artificial flies only and no trout possession, except children under 12 may keep one trout measuring 8–12 inches. Official rule |
| Lower High Banks–main river | Lower High Banks–main river: year-round fishing, artificial flies only. Brook and brown trout possession runs from the last Saturday in April through September 30. Rainbow possession is year-round. Daily limit: two trout, no more than one 18 inches or longer. Minimums: brook/rainbow 10 inches. Brown 18 inches. Official rule |
| Smith Bridge and downstream access | Do not confuse bank access with harvest rules. Confirm a legal approach or permission downstream. A navigable channel does not grant permission to cross private land. Official rule |
Named upstream end of the special-rule area. Use the mapped, posted approach. Check the route back before fishing late.
Site detailsUse designated parking and mapped paths for a walking plan. Camping and bank access are separate permissions. Follow signs.
Site detailsThe DNR map labels boat access here. Confirm posted access and downstream bank permission. This is not the Lower High Banks rule line.
Site detailsDesk review dated September 4, 2026. Live measurements update separately. No field visit, current hatch, catch report or access inspection is claimed.
Check what is allowed, where the rule applies, and whether the river is open.
Check the latest river reading and forecast before you leave.
Check public entry points, land rules, and seasonal access changes.
Use these links for stocking, safety, and other local details.
Check what is allowed, where the rule applies, and whether the river is open.
Open the current rules and check the river section, season, and special limits.
Open the current rules and check the river section, season, and special limits.
Open the current rules and check the river section, season, and special limits.
Check the latest river reading and forecast before you leave.
Open this page and check the latest safety advice before your trip.
Open this river reading to check the latest level, flow, and update time.
Check public entry points, land rules, and seasonal access changes.
Open the land or access page, then check signs before you park or enter.
Use these links for stocking, safety, and other local details.
Open this page for more river information and check when it was last updated.
Open this page for more river information and check when it was last updated.
What was checked: Desk review of USGS, NWS and Michigan DNR sources. No field visit, current hatch, catch, access inspection or safe-wading assessment is claimed. Live observations have their own timestamps.
Live measurements and forecasts keep their provider timestamps. Rules, access, and trip guidance use the source-review date shown here. BlueStreamFly planning advice is editorial interpretation, not an agency notice.
First-hand experience: BlueStreamFly does not claim a first-hand visit or local field test for this report unless a real contributor is explicitly named and linked.
Michigan’s South Branch through the Mason Tract and downstream to the main river. The main river Au Sable and New York’s Ausable have separate reports, gauges and rules.
Yes. USGS 04135700 near Luzerne supplies flow, stage and measured water temperature when available. Both seven-day charts use that station. It does not measure every fishing spot.
Yes. The /100 planning score responds to current flow, its trend, measured water temperature, recent heat and weather. Stale or missing key inputs can withhold it. It is not a safe-wading certificate or catch prediction.
At Lower High Banks, not Smith Bridge. The two named South Branch sections remain artificial-flies-only with different possession provisions. Read the reach details and current DNR order before fishing.
Match the actual insect’s size and stage with a locally verified pattern. The pictured sulphur, caddis and soft-hackle choices are not exact substitutes. Scout access before dark, bring backup lighting and check water temperature.
No. The rating is a bank/protected-edge trout plan, not an assessed float itinerary. This is not a claim that paddling is prohibited. A float needs its own launch, takeout, shuttle, suitable craft, PFD and conditions check.
