Missouri River (Canyon Ferry Dam to Toston / upper segments public FAS)

Explains stage, discharge and the stage-discharge relation. Read this before treating a gauge number as if stage and flow were interchangeable.

What the gauges actually record — stage every fifteen minutes, converted to discharge through a rating curve built for that one site — and why some sites will never show you a flow number at all. This is what makes a gauge page legible rather than a squiggly line.

The short version of gage height against discharge, and of gage datum — the per-site reference point that means 4.2 feet at one gauge has no relationship to 4.2 feet at another. Read it before you compare two gauges or treat a stage number as a depth.

Why it made the list: Re-read 2026-09-26: defines gage height as the stream or lake water surface above the gage datum, so it applies to lake and reservoir level gauges too.

Why water temperature drives dissolved oxygen, and how a lake separates into layers through the season, with temperature-depth profiles from a real lake across May to October. The general-principles piece behind every seasonal temperature question in this app.

A working example of what a Corps district publishes: pool and tailwater elevations, storage, hourly project data and proposed generation schedules. Use it as the template for finding the equivalent page for whichever district operates your reservoir — every district runs one.

Daily reservoir and river operations across the five Reclamation regions, including the hydromet systems and the RISE portal. Reclamation rather than the Corps operates most western reservoirs, so this is where those levels and releases live.

The three stages of cold water immersion, and the part most anglers have wrong: cold shock can be triggered by water as warm as 77°F, so a mild air temperature tells you nothing. Read it before spring wading and before any early-season boat or shore trip.

EPA's hub, including the route to current state, tribal and local advisories. Advisories are issued locally rather than federally, so this is how you find out whether one specific water is under one right now.

What a bloom looks like in the water — foam, scum, a spilled-paint surface — and the exposure routes for people and for dogs. The practical rule is to stay out of discoloured or foul-smelling water and check the local advisory first.

Clean, drain, dry as an actual procedure rather than a slogan: rinse the hull and gear, flush the motor, drain bilge and livewell before you leave the access, dry five days or towel down, bin unused bait. Written to be done every water, every time.

A good model of how a state regulations system is built: an annual pamphlet of statewide rules, water-specific exceptions that override them, and an emergency rule feed that supersedes the printed pamphlet mid-season. That three-part shape is near-universal, so it teaches you what to go looking for in your own state.

A state identification index covering the 162 species in Minnesota waters, with a downloadable poster and a fish-families guide. Most agencies publish an equivalent, and the agency version is the one whose names match the regulations booklet.

A numbered launch sequence done before joining the line: watch a launch or two to see how wind, current and the ramp's drop-off behave, then rig, pull tie-downs, check the plug and set bow and stern lines. It ends when the boat leaves the trailer, so retrieval needs another source.

Why it made the list: Re-verified 2026-09-26: page loads; the pre-line preparation steps, back-down and release steps, and a note on steep drop-offs at coastal ramps are present, with no retrieval section.

Shows what one state access directory does and does not promise: accesses are open 24 hours unless posted, carry no launch fee unless inside a park that needs a vehicle permit, and suit roughly 12- to 18-foot boats at most ramps. The condition of one specific access is a separate lookup through Lake Finder, which is the step a directory listing skips.

Why it made the list: Re-verified 2026-09-26: page loads; the hours, fee, trailer/carry-in and boat-size statements are present, with the instruction to check a specific access via Lake Finder or an area office.

The retrieval half of the ramp: back in only until the boat floats, winch it on at slow speed instead of driving it on, and look for scour holes and sediment mounds at the ramp's end, which get worse at low water. It is written to protect the ramp and says little about etiquette.

Why it made the list: Re-verified 2026-09-26: page loads; explains how prop wash digs holes and builds a mound at the ramp end, and gives the check-the-ramp, winch-don't-race and float-don't-submerge steps.

Separates two questions a map pin blurs: whether the water is public, and whether there is a lawful way onto it. A navigable stream through private land can be fished, but that gives no right to cross posted land to reach it, and Pennsylvania publishes no list of which waters are navigable.

Why it made the list: Re-verified 2026-09-26: page loads; the FAQ states the public may not cross private property to reach public waters, that lawful entry is through a public access point, and that no list of public waters exists.

Treats the inspection station as part of the trip clock: which boats must be inspected before launch, what to have ready so it goes faster, and how an intact seal with its receipt shortens the wait. Colorado's program; other states' stations keep their own hours and rules.

Why it made the list: Re-verified 2026-09-26: page loads; Know Before You Go preparation steps, the green seal and receipt program (with express lanes at some stations) and decontamination triggers are present.

How a boundary river changes the rule question: depending on the neighboring state, anglers follow the rules of the state they are in, the state that licensed them, or the stricter of the two, and tributaries need that state's own license. The Kentucky agreement defines the river by a gauge reading at Cairo, so the legal water moves with the level.

Why it made the list: Re-verified 2026-09-26: page loads; a table by river and neighboring state shows which regulations apply and the bank and backwater privileges, plus the 33-foot Cairo gauge definition.

What to do once fog is on the water: slow down, run lights in daylight, listen for engines and buoy signals, and hold position somewhere safe if bearings are lost. It is written with open water and shipping lanes in mind, and lists GPS as a way to fix position, which is not the same as seeing traffic or the landing.

Why it made the list: Re-verified 2026-09-26: page loads; the under-one-mile dense fog definition and the slow-down, lights, listen, radar, GPS/chart, stay-put, sound-signal, compass and avoid-shipping-lanes steps are present.

Explains the fogs that close inland water: radiation fog on clear, calm nights, valley fog that pools on the valley floor and usually lifts soon after sunrise, and steam fog when cold air moves over warmer water. The safety advice is written for drivers, so the page helps with timing a trip, not with handling a boat in fog.

Why it made the list: Re-verified 2026-09-26: page loads; sections on radiation, valley, advection, freezing, steam and frontal fog are present, with a photo of fog moving in off the Ohio River.

The controlling text, on inland waters as well as at sea: Rule 5 requires a look-out by sight and hearing, Rule 7 warns against assumptions from scanty radar information, and Rule 19 requires a safe speed for restricted visibility. It is legal text, not a tutorial, and small lakes outside federal navigable waters fall under state boating law instead.

Why it made the list: Re-verified 2026-09-26: page loads; Rules 5, 6, 7(c), 19 and 35 are present, with the Inland differences marked.

Defines riffle, run, pool and glide by what causes them — substrate size, gradient, position on a meander — rather than by how they look, and shows how the sequence repeats down a reach. It gives you the vocabulary before you start deciding where to fish.

Adds the small-boat detail the agency pages skip: a long, shallow fetch such as Lake Erie builds short, steep chop, waves running against a current stand up, and a forecast still needs checking against the horizon once out. It is a general boating study guide, so it says little about paddle craft or the landing shore.

Why it made the list: Re-verified 2026-09-26: page loads after redirect from boatus.org/study-guide/planning/weather; sections on wind and current effects, fetch and whitecaps, shallow-water chop, scanning the horizon and taking gusts on the bow are present. A nonprofit source, used because no agency page found explains fetch for inland small craft.

Twelve short lessons on current, cover, pool tails, big rivers, pocket water, floods and droughts. The examples are trout-heavy; the current-reading mechanics travel farther than that.

Why it made the list: Re-verified 2026-09-08: page loads, all twelve segments present. Established instructional series with the whole chapter in one place.

A compact worked example of depth, overhead cover and food supply in an ordinary straight reach. Useful after the schematic because it shows the same questions on real water.

Why it made the list: 6,801 views and 142 likes observed 2026-09-08; The Orvis Company channel, 112K subscribers, published 2020.