Question: The town of Riverhead rests on the mouth of which river that drains an area between the Harbor Hill and Ronkonkoma terminal moraines?
Context: Riverhead is a town within Suffolk County, New York, on the north shore of Long Island.  As of the 2010 census, the population was 33,506.  The town rests on the mouth of the Peconic River, from which it derives its name.  Since 1727, Riverhead has been the county seat of Suffolk County.  The smaller hamlet of Riverhead lies within it, and is the town's principal economic center.  The town is 166 miles (267 km) southwest of Boston via the Orient Point-New London Ferry, and is 76 miles (123 km) northeast of New York City. The glacial history of Minnesota is most defined since the onset of the last glacial period, which ended some 10,000 years ago.  Within the last million years, most of the Midwestern United States and much of Canada were covered at one time or another with an ice sheet.  This continental glacier had a profound effect on the surface features of the area over which it moved.  Vast quantities of rock and soil were scraped from the glacial centers to its margins by slowly moving ice and redeposited as drift or till.  Much of this drift was dumped into old preglacial river valleys, while some of it was heaped into belts of hills (terminal moraines) at the margin of the glacier.  The chief result of glaciation has been the modification of the preglacial topography by the deposition of drift over the countryside.  However, continental glaciers possess great power of erosion and may actually modify the preglacial land surface by scouring and abrading rather than by the deposition of the drift. The Harbor Hill Moraine, in the geography of Long Island, forms the northern of two ridges along the "backbone" of Long Island.  The Harbor Hill Moraine, skirting the North Shore, represents the terminal moraine of the most recent advance of the Wisconsinian glaciation, which reached its most southward advance about 18,000 years ago; the earlier Ronkonkoma Moraine, much cut through by outwash streams from the Harbor Hill Moraine, lies to the southeast.  The Harbor Hill moraine is represented by the North Fork of eastern Long Island and in three disjunct sections farther east, Plum Island, Great Gull Island, and Fisher's Island. Located in Collegeville, Minnesota, Saint John's Arboretum encompasses over 2500 acre settled by Benedictine monks in 1864.  Since its founding, the abbey has been guided by the Benedictine principles of stability, hospitality, and stewardship.  In 1997, this longstanding principle of stewardship led the monks to designate the lands of Saint John's University as a natural arboretum.  Saint John's Arboretum is advantageously located in the unique area of terminal moraines (glacial deposits) that distinguish central Minnesota.  The varied terrain and its location between the hardwoods and prairies creates considerable diversity in the habitats found there. The Fulde belongs to the Weser river system in Germany.  It is about 11 km long and flows entirely within the territory of the borough of Walsrode (Heidekreis district, in the state of Lower Saxony).  It rises in a valley between two parallel end moraines formed in the Saalian Ice Age.  By far the largest source drains the Grundloses Moor ("bottomless moor"), 4 kilometres north of Fulde and emerges from the "Kleiner See" ("Little Lake") there.  Another source appears 2.5 kilometres northwest of the village of Fulde, which gave the stream its name.  From there the Fulde runs through, at times, picturesque scenery between steep, grass-covered, clay banks and fish ponds south of the Walsrode town forest of "Eckernworth", where the Rischmannshof Heath Museum is located, crosses the centre of the town through the "Fulde Park" with its town hall and joins the River Böhme south of the monastery lake. Quaternary Icefall ( ) is a western lobe of the Mount Bird icecap, descending steeply into Wohlschlag Bay 1 mile (1.6 km) south of Cinder Hill on Ross Island.  The site was mapped and so named by the New Zealand Geological Survey Antarctic Expedition (NZGSAE), 1958–59, because of the Quaternary glacial period marine shells carried by the glacier and deposited in terminal moraines. The Blue Lake is one of only four cirque lakes found in mainland Australia, the other three, Cootapatamba, Albina, and Club are shallower than BL and are held entirely by terminal moraines.  Its valley contains the best-developed glacial features in the Kosciuszko National Park alpine area of New South Wales.  It was recognised as a wetland of international importance on 17 March 1996 when a 320 ha area, comprising the lake and its surrounds, including nearby Hedley Tarn, was designated Ramsar Site 800 under the Ramsar Convention on wetlands. The Nashville Terminal Subdivision is a railroad line owned by CSX Transportation in the U.S. State of Tennessee.  The Subdivision is broken up into 5 sections all in Nashville, Tennessee.  The northern part of the Terminal is in Madison, Tennessee at milepost 000/0BA 174 on the southern end of the Ex-L&N Mainline Subdivision at Monfort.  Disptach for the Mainline Sub is known as "LD" which is part of the Cincinnati Division.  From here in Madison begins the double track that stays for another 22 miles south to Brentwood, Tennessee.  At milepost 000/0BA/00H 176.6, the famous Johnny Cash "Amqui" location where the Ex-L&N Evansville, Indiana line, the Henderson Subdivision meets with the Terminal.  Dispatch for the Henderson Sub is known as "SA" and operates on AAR58.  There are two crossings near each other, Williams Ave and Nesbitt Lane at Amqui.  From here the Terminal goes south about 2 miles to the Nashville National Cemetery to the first major location, known as Ekin, 000179, where there is a cross over track from number 1 to number 2 track (left to right track).  There is also the first EDD (Defect Detector) at 000179.1.  Few more miles southward, the next major location appears.  At 000181.0, Maplewood is a major location for the Terminal.  From here the regular Terminal goes south to swap crews at Kayne Ave, and the right side, Radnor Cutoff, detours the city and gives yard departures and arrivals direct access to and from Radnor yard to cities like Louisville and Chicago.  The Cutoff runs from Maplewood to Shelby Park double track.  From Shebly the track converges into one to pass the historic Shelby bridge, then it opens back to double track.  From there, the cutoff hits the Intermediates at 0BA187.0 known as Chicken Pike.  The Radnor Cutoff carries the L&N mainline classification of "0BA" but meets the main at the same milepost from the Terminal.  At Chicken Pike, trains are staged to await arrival to Radnor yard.  Once they get clearance, speed is decreased to 15, and at 0BA188.1 the EDD (Defect Detector) sounds for departures and arrivals.  This location is known as North Radnor.  The right track diverging from the #2 is known as A-1, it is for departure trains to Chattanooga and Atlanta.  The left track which goes west from the #1 is known as A-2, and serves as a departure track to Memphis, and if the cutoff is out of service, all northbound departures.  The interesting piece of Maplewood is the crossovers that are there to move trains from the Cutoff to the Main.  Both lines remain double track for a while.  The main runs south for 2 more miles until the Intermediate signals at 000183.0.  Commonly trains will stop before Delmas Ave when Kayne Ave is at capacity and await dispatch permission before moving south.  From here, the main continues south until the CR Cumberland River Swingbridge, where the main converges into a single track shortly to cross the bridge.  At this point, trains had been running at track speed of around 40.  From the drawbridge into town, speed is reduced to around 10.  After the bridge is passed, the main returns to double track in downtown.  On the #1 track about a half a mile south, another connecting track is present.  This is the Wye track that connects the main with the Bruceton side, while rarely used for mainline trains, locals and river jobs use it.  The location is known as 8th Avenue or 8th Avenue Wye.  The main then runs down to Kayne Ave, the central hotbed of all Nashville thru traffic.  The Memphis, Tennessee Ex-L&N Bruceton Subdivision meets with the Terminal.  The Bruceton Sub begins at Church Street at 00N0.0.  The line then runs single track until 00N0.7 "11th Avenue" where it turns into double track and also meets the aforementioned, Wye track.  The Bruceton line then goes southwest a while to the next signals, at "Shops".  Now speed has been increased.  The line is still double track until "Sellars", where speed is increased to 40 and jurisdiction transferred to the SD Dispatcher.  For a short time, 4 main tracks are present and an additional fifth track for switchers and yard movements.  The tracks from left to right in Kayne Ave are as follows: 100, 99, 98, 12, 3.  The Kayne Ave yard is also here in this area, which houses some frieght and some switcher engines.  The tracks to the old shed are covered and removed.  The Union Station is not an active station, but a historic hotel.  Crew change usually occurs at the "walkway" which is under the Demombreun St bridge by the Kayne Ave Tower.  This is also where the Ex-NC&StL Chattanooga Subdivision begins.  Then tracks run south to Fogg St/South End where things get complicated.  At milepost 000/0BA/00J187 the 98 track merges into the 12 track, making for 3 tracks now.  There is a crossover from 99 to 12, also a crossover from 12 to 3.  About 2/10ths of a mile down the 99 merges into the 12 track reducing the tracks back to the regular double.  About 4/10ths of a mile down the line from Fogg St, 000187.4, Oak St, is a crossover track from #2 to #1 (the track names are no longer 3 and 12, but are back to regular names).  When trains use this crossover northbound, such as Memphis bound trains from the A-2 line, they refer to it as "Long Lead".  And now, the Terminal splits into two parts.  The right side turns into a single track shortly, and will become the Chattanooga Subdivision, and the left side runs south to Brentwood.  The right track runs single shortly until double track for a while.  This begins part of the Chattanooga Sub or J-Line.  The #2 meets with the A-2 connection track at 00J2.2 known as A-2.  Speed is now increased to 40.  Commonly northbounds will stage at 4th Ave on the #1 to await clearance.  Now about a mile down the #1 meets the A-1 connection line.  At 00J3.6 known as A-1.  Further down the double track ends at Glencliff (00J4.9).  Now it runs single for three miles until it hits Danley, which has the D Line connection track, which is an arrival track for incoming Radnor trains from the J Line.  At Danley, the Terminal ends but the same dispatcher handles traffic, "SC".  At Oak Street, our main terminal line goes south two miles to 000189.0 known as Criaghead or Vine Hill.  There is a crossover here from #1 to #2 track.  And there is also a connection/delivery track to the Nashville and Eastern Railroad which connects the Tennessee Central Railroad Museum to a major railroad.  Trains sometimes stop on the #2 before Craighead if they are waiting to enter Radnor yard.  Sometimes trains wait on the #1 at the Berry Road crossing if they await arrival to Kayne Ave. At this point, speed has been increased to 30 from 10.  Moving south, the line hits Radnor Yard at 000192.  The #2 track meets the E-Line arrival track which most Memphis trains and locals use.  The B-Line which meets the #1 track is used for departures out of the C yard and local jobs.  At Mayton, 000192.3, the B line meets the #1 track, and there is a crossover track from #2 to #1.  Speed is now at 40.  2 miles south, at 000194.0, South Radnor, the next intersection is present.  This is where the Radnor A yard meets the main.  There is a single departure/arrival track that meets the #2 track along with a crossover from #1 to #2 track.  Commonly, the #2 track south of the signals is used to halt trains.  This location is known as TVA, because of the power station that is adjacent.  From here the Terminal runs about 2.5 miles south until we hit the southern tip.  The tracks converge onto one single main, at 000/0BA196.6 known as Brentwood.  Speed is increased to 50 and jurisdiction to the S.E. dispatcher.  The right track is the main, S&NA North, while the left track is the Nashville Subdivision which runs to Columbia and exchanges freight with the TSRR.  The Nashville Terminal Subdivision is one of the busiest locations on the CSX network, and one of the most important. The Peconic River is a river within Suffolk County on Long Island, New York in the United States.  The river is located in the eastern end of Long Island.  The Peconic River drains an area between the Harbor Hill and Ronkonkoma terminal moraines, and flows into Flanders Bay which in turn connects to Peconic Bay east of Riverhead. Jayne's Hill (also known as High Hill, West Hills, Oakley's Hill, and Janes Hill) is the highest point on Long Island, New York, with an elevation of between 387 ft and 400.9 ft above sea level.  It is situated on the Harbor Hill moraine, a terminal moraine that makes up the northern spine of Long Island in West Hills County Park in Suffolk County, a little more than a mile to the north of Melville.
Answer: Peconic River