The sun had sank below the surrounding Catskill Mountains when guide Wayne Aldridge pegged his drift boat into position by releasing the anchor that suspended from the craft's stern.

A few moments earlier he's spied a nice brown feeding on the surface, likely taking one of the caddis or Isonychia mayflies that had been sporadically hatching.

Under Aldridge's direction I made a reach cast that angled slightly downriver but laid the line upriver so the fly wouldn't immediately drag.

Then I paid out loops of line so the fly could drift drag- free past the trout's last location.

In typical Upper Delaware River fashion, the trout rose and sipped a nearby natural, ignoring my Iso imitation — maddeningly frustrating yet exciting.

A short while later Aldridge anchored the boat just upstream of another pod of risers.

Dave Keith, again under Aldridge's tutelage, presented a cream-colored caddis fly. A 17 inch brown trout ate it without hesitation. A few minutes later it was securely in the net.

The Upper Delaware River — which encompasses the East Branch, West Branch, and upper portion of the main stem – supports one of the better wild trout fisheries in the region. Many consider it the best dry fly fishing for outsized stream-bred browns and rainbows east of the Mississippi River.

Like many of the nation's better waters for large, wild trout, the upper Delaware is somewhat of an 'artificial' fishery, one made possible due to the cold water releases via bottom discharges from upriver reservoirs.

In this case both the East Branch and West Branch have reservoirs, Pepacton and Cannonsville respectively.

Pepacton and Cannonsville serve primarily to furnish water to New York City. Combined with two other Catskill impoundments — Neversink and Roundout — they provide around 80 percent of the city's water supply needs.

A first-class trout fishery was an unplanned outcome of the creation of the Upper Delaware reservoirs, projects that spanned the period from the 1930s through the 1950s. Water releases are made with NYC's needs in mind, not that of the downriver trout population. While a minimum flow in the Delaware River basin is required – a projected flow of 1,750 cubic feet/second at the USGS gauge at Montague, NJ — releases from the reservoirs are inconsistent.

Cold water is the life blood of a trout fishery; they need what the reservoirs provide.

Inadequate releases stress fish and play havoc with aquatic bug life. Discharge policies have been and continue to be a point of contention between the angling public and New York City DEP, who operates the impoundments.

Trout fishing within the Upper Delaware means adjusting locations and tactics with present discharges, something that tends to change rapidly.

All of the East Branch and the majority of the West Branch flow through New York State. The lower 11 or so miles of the West Branch serve as the boundary between New York and Pennsylvania. The main stem of the Delaware is formed near Hancock, NY.

During the mid-October trip Dave Keith and I made we fished both the West Branch and the upper main stem. It was an outing I'd thought about for the past few years. Doing it in the fall meant that angling pressure would be comparatively light — this watershed is fished hard — but it also meant that insect activity would be far less that spring and early summer. But Dave and I don't like crowds, so it was a great time to learn about the area and how to fish during a return trip.

For that same reason we employed a guide rather than trying to learn it on our own. It was a good investment. We covered a lot of water in the drift boat and learned some tricks that will be useful during any future outings on the river's finicky trout.

New York's trout season ended as of Oct. 15. Our trip was a couple days prior to the closure. However the lower West Branch (where it becomes a border water) and main stem of the Delaware remain open to trout fishing on a catch and release basis.

Fewer trout might be in this stretch at this time of year however, as many will migrate upriver to find proper spawning conditions.

Pennsylvania anglers can legally fish the border water sections with their resident license.

One day non-resident licenses are available for $11 a day in New York.

Didymo algae is present in the Upper Delaware River. Anyone wade fishing that area should thoroughly clean their gear before fishing any other waters.

There are many online resources that explain such procedures in detail.

Jeff Knapp is a fishing columnist for the Butler Eagle