Hancock to Callicoon, from the Pennsylvania bank
The main stem begins about a mile below Hancock where the East and West Branches meet at Junction Pool, and the cold-water trout reach runs roughly 25 miles down to Callicoon before the river warms into smallmouth water toward Narrowsburg and Port Jervis. Pennsylvania owns the west bank the whole way. Access on this side is thinner than on the New York side, where Route 97 and the DEC lots at Lordville, Long Eddy and Callicoon sit close to the water, but the State Game Lands parking just south of Hancock, the Buckingham launch and a handful of pull-offs get you in. Most of the land is private and the roads stay away from the river, which is the first thing every guide says about the main stem.
It is big water with few islands and pools that run from an eighth of a mile to a mile and a half long, 4 to 10 feet deep. The drift boat is the standard tool. If you are wading, plan around one riffle and its tail rather than a mile of bank.
Rainbows in the riffles
Nobody stocks the main stem; the trout are wild, and below Lordville the rainbows outnumber the browns by something like six to one according to Gone Fishing Guide Service in Callicoon. They sit in the fast water and at the extreme heads of the pools, not in the middle of them. The Callicoon guide's approach on bright summer days is to row through the eddies and nymph the riffles: weighted bead-head Pheasant Tails 14 to 18, Brassies, Princes and Zug Bugs, a size 12 to 14 Isonychia emerger or a caddis pupa on a dropper under a small yarn indicator. Rainbows do not get going until the water reaches the mid 50s, usually around May 10; April is brown and brook trout time. Fish size runs bigger than the West Branch; leave the exact numbers to the DEC.
Hatches worth planning a trip around
Cross Current Outfitters in Starlight, on the Pennsylvania side above Hancock, publishes the dated chart. Hendricksons April 15 to May 25, Grannoms April 25 to May 25, Sulphurs of several species from April 20 into August, March Browns May 15 to June 5, Green Drakes June 1 to 15 and Brown Drakes June 5 to 15, Isonychia June 1 through October, Light Cahills June 5 to September 10, Tricos June 28 to October 15, and the White Fly August 20 to September 15. Blue-Winged Olives of one species or another are on the water from late March into November.
The Upper Delaware Inn's summer calendar matches it: Green Drakes at dusk in early June on the slower silty margins, Trico spinner falls at first light in July on the flats from Lordville to Long Eddy, evening tan and olive caddis all summer, and the White Fly on August evenings on the main stem from Long Eddy down. Sulphurs on the main stem come off late afternoon into dark. Bring 12- to 14-foot leaders and 5X or 6X; this is the most selective rising-fish river in the East and the fish have seen every fly.
What 1,200 cfs at Callicoon means
The two gauges to watch are Lordville and Callicoon. Gone Fishing Guide Service puts the wading line at 3.2 feet, which it equates to 1,000 to 1,200 cfs: below that you can wade the riffles, above 3.4 feet (about 1,500 cfs) the fishing is from a boat, and above 4 feet the river is dangerous. On this year's USGS readings at Callicoon 3.2 feet has run just under 1,000 cfs and 3.4 feet about 1,350, so the guide's numbers hold. This page compares the live gauge to 600 to 1,200 cfs; the top is the guide's line and the bottom is where the river sits in a dry August (the USGS median at Callicoon runs about 1,200 to 1,260 cfs from July through September, with the 10th percentile near 800).
Flow here is a reservoir decision. Cannonsville on the West Branch and Pepacton on the East Branch release cold water from June into September, so a 1,000 cfs day in July can be 60 degrees at Hancock and 70 at Callicoon. Carry a thermometer, check the Cannonsville release before you drive, and stop fishing for trout at 68 degrees.
Pennsylvania rules, New York rules, one license
The Delaware between New York and Pennsylvania is a boundary water. The 2026 PFBC summary says a Pennsylvania or a New York license is valid on the river, West Branch included, from a boat or from either shore, but you must follow the rules of the state whose water you are fishing. On the Pennsylvania side north of I-84 (which is all of the trout reach) the season for trout is April 4 at 8 a.m. through October 15, the minimum size is 14 inches and the daily limit is 1 trout. The West Branch has a separate no-kill artificial-lures-only season from October 16 until opening day. New York's regulations for its side of the main stem differ; check the DEC's Delaware County and Sullivan County special regulations if you cross the channel.
Bass are catch-and-release from April 11 through June 12, walleye on the New York-Pennsylvania portion are closed from March 15 to May 1, and American shad, which run April through June in the 52 to 66 degree window, have a limit of 2. There are no artificial-lures sections on the main stem itself.
Boat or wade
Float from Lordville to Long Eddy for the July Tricos and the terrestrial banks; float from Long Eddy toward Callicoon for the August White Fly and time the drift so dusk finds you on the last flat. Wade at Lordville and the riffles below the Buckingham launch when the gauge is under the guide's line. Hackett Fly Fishing runs mousing trips after dark on the main stem in summer, which tells you what the browns are doing while the rainbows sleep. The Upper Delaware is a National Park Service Scenic and Recreational River managed through the Upper Delaware Council in Narrowsburg, so the launches are public but the banks between them are mostly not.