Title: River Thame
Content:  The River Thame is a river in Southern England. It is a tributary of the River Thames. The general course of the River Thame is south-westward and it runs from each of the longest of its many sources to the River Thames in about 40 mi. The Thame rises in the English county of Buckinghamshire and discharges in south-east Oxfordshire.
Title: River Thames
Content:   The usually quoted source of the Thames is at Thames Head (at ). This is about 3/4 mi north of Kemble parish church in southern Gloucestershire, near the town of Cirencester, in the Cotswolds. However, Seven Springs near Cheltenham, where the Churn (which feeds into the Thames near Cricklade) rises, is also sometimes quoted as the Thames' source, as this location is farthest from the mouth, and adds some 14 mi to the river's length. At Seven Springs above the source is a stone with the Latin hexameter inscription "Hic tuus o Tamesine pater septemgeminus fons", which means "Here, O Father Thames, [is] your sevenfold source". The springs at Seven Springs flow throughout the year, while those at Thames 
Title: Thames River (Ontario)
Content:  There are three rivers in the watershed with Thames in the name—the Thames River itself, North Thames River, and Middle Thames River. These are also known locally as South Branch, North Branch, and Middle Branch. The South Branch, which begins near Tavistock and initially flows southeasterly before turning southwesterly towards Woodstock, is the main stem Thames River and officially carries the Thames River name. The Thames River and North Thames River in the upper part of the watershed flow through valleys created during the retreat of the glaciers during the last ice age. The Thames River and North Thames River meet in central London at the "Forks"; the University of Western Ontario 
Title: River Thames
Content:   Researchers have identified the River Thames as a discrete drainage line flowing as early as 58 million years ago, in the Thanetian stage of the late Palaeocene epoch. Until around 500,000 years ago, the Thames flowed on its existing course through what is now Oxfordshire, before turning to the north-east through Hertfordshire and East Anglia and reaching the North Sea near present-day Ipswich. At this time the river-system headwaters lay in the English West Midlands and may, at times, have received drainage from the Berwyn Mountains in North Wales.
Title: Thames Head
Content:  Thames Head is a group of seasonal springs which, when flowing, form the headstream of the River Thames, the major river which runs through the South of England and the centre of London. Their location is in fields near the villages of Coates and Kemble, on either side of the A433 road, about three miles south-west of the town of Cirencester, in the Cotswolds, Gloucestershire. The field to the north of the A433, Trewsbury Mead, has the highest-located springs, which tend only to flow during a wet winter. One of these springs is marked with an inscribed stone marker. Below it, the springhead itself is in a hollow that has been lined with stones. Thames Head is 360 ft above sea level, at grid reference ST980994. The actual start of the River Thames changes as the level of groundwater changes. The spring known as Lyd Well, located south of the A433 (grid reference ST989984), is often where the river starts. In 2011, the lowest recorded start of the Thames was just upstream of Ashton Keynes, which is over 6 miles (10km) downstream from Thames Head.
Title: River Thames
Content:  The River Thames, known alternatively in parts as the River Isis, is a river that flows through southern England including London. At 215 mi, it is the longest river entirely in England and the second-longest in the United Kingdom, after the River Severn. It flows through Oxford (where it is commonly called the Isis), Reading, Henley-on-Thames and Windsor. The lower reaches of the river are called the Tideway, derived from its long tidal reach up to Teddington Lock. It rises at Thames Head in Gloucestershire, and flows into the North Sea via the Thames Estuary. The Thames drains the whole of Greater London. Its tidal section, reaching up to Teddington Lock, includes most of its London stretch and has a rise and fall of 23 ft. Running through some of the driest parts of mainland 
Title: Thames Head
Content:  The claim that this site is the source of the River Thames is disputed. The Environment Agency, the Ordnance Survey and other authorities have the source of the Thames as Thames Head. Others hold that the true source of the Thames is at Seven Springs, Gloucestershire, some 11 mi farther north, and east of Gloucester. Seven Springs is officially the source of the River Churn, which is a tributary of the Thames that joins at Cricklade. As it is further from the mouth of the Thames than Thames Head, the adoption of Seven Springs as its source would make the Thames the longest river in the UK.
Title: Thames Path
Content:  The Thames Path uses all available riverside rights of way between the traditional source of the river in Trewsbury Mead and Inglesham, but is unable to run alongside the river in several places. The Thames Path starts beside the monument for the traditional river source and follows the water down the hill towards the Fosse Way. In the fields either side of the A433 are some springs; and south of this road, a small water channel can be found and then a small weir, before reaching the A429 bridge near Kemble. On the stretch between Ewen and Somerford Keynes the bourne passes through fields and there 
Title: Stream capture
Content: The River Thames in southern England originally entered the North Sea near Ipswich. About 450,000 years ago, an ice sheet expanding from the north pushed the course of the river southwards, forcing the Thames to cut a new mouth where the mouth of the River Blackwater, Essex now is, north of London. It later moved southwards again to its current position as a result of cutting through the Chiltern Hills at Goring-on-Thames, an event which created the Goring Gap. 
Title: Thames River (Ontario)
Content:  The Thames River is located in southwestern Ontario, Canada. The Thames flows southwestly 273 km through southwestern Ontario, from the Town of Tavistock through the cities of Woodstock, London and Chatham to Lighthouse Cove on Lake St. Clair. Its drainage basin is 5825 km2. The river is also known as Deshkan Ziibi (“Antler River”) in the Ojibwe language, spoken by Anishnaabe peoples who together with the Neutrals have lived in the area since before Europeans arrived. In 1793, Lieutenant Governor John Graves Simcoe named the river after the River Thames in England. French Canadians (and all other French-speaking peoples) also call the river by this name, and not by the exonym Tamise. Much of the Thames was formerly surrounded by deciduous Carolinian forests, but much of this forest has been removed to permit agriculture and other forms of development. Two conservation authorities together have jurisdiction over the Thames River watershed (the Upper Thames River Conservation Authority and Lower Thames Valley Conservation Authority), and work to prevent damaging floods, as well as undertake other resource management activities.

Question: where does the thames river begin and end?
Answer: Lighthouse Cove.
Near Tavistock.