It may be also be applied more broadly to include an additional postulated extension of this structure, incorporating ancient monuments numbers 1004108 and 1004104 which extend to the north and south of Wheeldale for up to 25 miles (40 km).

They interpreted the structure as a causeway across marshy ground, attributing its construction to the Roman military, an explanation that remained largely unchallenged throughout the remainder of the eighteenth and nineteenth centuries.

In the late twentieth and early twenty-first centuries, its identification as a Roman road has been questioned by academics, and alternative interpretations suggested for its purpose and date of construction, including its possible origin as a neolithic structure up to 6,000 years old.

[23] Codrington and archaeologist Frank Elgee consider the structure was flanked in a few sections by lateral parallel ditches,[24] but Hayes is doubtful whether they were part of the original construction or if they even existed.

[28] In 1855, several overgrown fragments of the structure were also reported visible at several points in the vicinity: near Morley Cross; east of Keys Beck; near Hazle houses; at July Park; and Castle Hill.

[13] Early records of the causeway's course to the north—when its remains were apparently more readily visible than today—differ considerably from one another:[30] the early geologist and natural historian George Young, who wrote concerning the causeway in his History of Whitby, makes no clear mention of the route of the structure north of Wheeldale Moor; it is unmarked on the 1854 Ordnance Survey map of the area, and eighteenth-century historian Thomas Hinderwell's mention of it passing near Hunt House suggests a greatly differing route to that marked on 2012 Ordnance Survey mapping.

[32] Beyond Julian Park, it has been conjectured that the structure originally continued to the Roman garrison fort at Lease Rigg, southwest of Sleights, based on reports from antiquarians in the eighteenth and nineteenth centuries that fragments were visible at numerous points along this course.

[33] Numerous authors have conjectured that the structure was a road that continued past Lease Rigg all the way to Roman coastal fortifications or signal stations somewhere near Whitby,[14] but this is debated.

[44] Hayes and Rutter failed to find any trace of the causeway south of Cawthorne along a route via Amotherby, Barugh or Newsham in their survey in the 1950s,[21] and note that its course could not be determined as early as 1726.

[23] In 1890, historian Thomas Bulmer records that: [Wade] is represented as having been of gigantic stature ... His wife ... was also of enormous size, and, according to the legend, carried in her apron the stones with which her husband made the causeway that still bears his name.

Walter Map, writing in the twelfth century, also mentions a Vandal prince Gado (thought to be a Latin form of Wade[62]) in his fantastical lay De Nugus Curialium.

[34] Various authors suggest links to the giant Vaði, (also known as Witege, Vathe, Vidia, Widga, Vidga, Wadi or Vade) mentioned in the Norse Saga of Bern in the Þiðrekssaga;[35] the Danish hero Wate, also called Wada;[64] the Anglo-Saxon deity Wōden (also Wōđanaz or Wōđinaz),[36] who was historically referred to as "heaven's giant";[65] and the German figure Wa-te, a fierce sea-king similar to Neptune, who reigns in Sturmland in the 7th-century saga Kudrun.

[37] Nurse and Chadwick identify all the above figures as being later facets of a single legendary character present in early, shared mythology of tribes living around the rim of the Baltic and North Seas.

[38] There are possible etymological links between Wade's causeway and other UK archaeological sites: the Wansdyke that runs between Wiltshire and Somerset; Wat's Dyke in the Welsh borders; and perhaps most significantly the relatively-local "Waddes Grave"[66] at Mulgrave near Whitby:[67] all three have pre-modern origins and two have sections contested as Roman in part.

[73] The sixteenth-century antiquarian John Leland passed through the area in around 1539 when compiling his Itineraries of local English history and mentions the nearby and mythologically-linked "Waddes Grave"[66] – standing stones at Mulgrave near Whitby.

[48] Working alongside Oxley Grabham from the York Museum,[5] members of the Yorkshire Archaeological Society and several private individuals, Patterson cleared and excavated the adopted stretch of the causeway between 1910 and 1920.

[87] The Royal Commission on the Historical Monuments of England (RCHME) undertook a theodolite survey of the causeway in 1992,[81] and some limited excavations and analysis were carried out in 1997 during maintenance work on the structure.

[51] Professor Pete Wilson, on behalf of English Heritage's Portico Properties Research Project, has suggested questions for future research and investigation of the site, including excavation to establish its date and function; examination of historical documentation for medieval mention of the use of the monument as a route or in a boundary dispute; and analysis of the site via a detailed aerial survey, lidar or other remote sensing technique to establish the extent of the monument beyond the length so far excavated.

[88] The possibility also exists to apply newer techniques such as optically stimulated luminescence (OSL) testing to attempt to date any bricks, pottery, or other fired materials found in situ in the structure, a method that was successfully used in the identification of a suspected Roman road near Bayston Hill in Shropshire.

Agricola made a concerted effort to expand and consolidate Roman control over lands of the Brigantes tribes in the North York Moors area in the 80s AD[63] and is thought to have ordered the construction of nearby Lease Rigg fort.

[64] The east coast of the North York Moors area formed the northern flank of the Saxon Shore defences believed to have been constructed against this perceived threat.

An alternative, or perhaps secondary, usage for the causeway in Roman times is suggested by landscape author Michael Dunn and others, who state that it may have been constructed for the transport of jet inland from Whitby.

[75] Whilst nineteenth- and to a lesser extent twentieth-century[76] attitudes often suggested that any well-constructed pre-modern road surface must be Roman,[77] late-twentieth-century archaeologists were more open to evaluating the structure within the context of a wider span of historical periods.

[78] Twenty-first-century archaeologists then found several exemplars of other cambered, metalled roads that pre-date the Roman presence in Britain,[79] and hence set precedence for the possibility of a pre-Roman origin for the Wheeldale causeway.

[34] Archaeological consultant Blaise Vyner suggested in 1997 that the structure may be the collapsed and heavily robbed remains of a Neolithic or Bronze Age boundary wall or dyke.

[53] One possibility that could explain several of the anomalies in trying to identify the site definitively is the suggestion by Knight et al. that it was commonly observed practice in the area for dykes to be reused as trackways.

[124] Archaeologist James Maxim in 1965—a year after Hayes and Rutter published their findings on Wade's Causeway—stated that he had found a medieval pack-horse trail passing under Blackstone Edge,[125] which it must therefore post-date.

[128] There are specific mentions of damage to the causeway through ploughing,[86] tree felling, the laying of water mains, attempts to clear vegetation[111] and even, in the twentieth century, by the activity of both tracked [129] and armoured[130] vehicles.

[94] Updates by the North York Moors National Park Authority and English Heritage suggest that natural weathering[95] and grazing sheep[134] represent greater erosion risks to the structure than do human agents.

[96] Scottish Author Michael Scott Rohan drew on the legend of Wade's Causeway, as well as wider English, Germanic, and Norse mythology, when he wrote his Winter of the World trilogy while living in Yorkshire.