Taking it to the edge: did you know? Historic trees or trail blazing

Most explorers marked their passage across the land, either by blazing trees or erecting cairns of stones or similar marks. This was not a random or wantonly destructive exercise, but 'precisely identified the routes they took and the points where they made observations.' (Porter)  Explorers were frequently given quite precise instructions by the expedition organisers: for instance the South Australian Government instructed John McKinlay (appointed leader of the Burke and Wills Relief Expedition in 1861) 'You are advised to make frequent cairns of stones, or conspicuous marks on any convenient trees you may find-depositing information in the tin cases-so that your course may be followed on any future occasion, and you are particularly requested at all times to use, as your distinguishing mark the letters M K conjoined, thus MK' (South Australian Parliamentary Paper no. 147/1861)

Similarly in the Handbook of instructions for the guidance of the officers of the Elder Scientific Exploration Expedition page 8 'The Leader will cause all important camping places to be marked on the ground as permanently as possible. Where there are trees, they should be marked, after removing a sheet of the bark, by cutting with a chisel the initial letters of his name, with the date and number, thus:- D.L. No. 1. 16-4-91. Rocks may be similarly marked, or cairns of stones built and particulars placed beneath them. Where it is convenient, such small cairns of stones should be erected on hill tops, and if the name of the hill has been determined, it should be shown on the record left.'

Some blazed trees still stand in the landscape today, though in some cases they have died, or else the blaze has grown over with time.  The 'dig tree' of Burke and Wills fame has been placed on the National Heritage Register and has protective fencing. Its health is closely monitored by the Queensland Environmental Protection Agency.  William Hovell's tree on the banks of the River Murray at Albury has been cloned. (http://www.csiro.au/files/mediaRelease/mr1999/ClonesGiveNewLeaselifeTo.htm)

The lost Leichhardt expedition of 1848 was traced as far as its last camp somewhere west of Roma in Queensland. Subsequently reports came in of trees blazed with an 'L', some along the Cooper's Creek. This is an example of blazed trees guiding the path of later explorers. Unfortunately in the case of Leichhardt no further traces of his expedition have ever been found.

Blazing trees or raising stone cairns were standard surveying techniques-even Colonel William Light raised a flagstaff on a hill, as a high point for his surveying triangulation-hence the Adelaide suburb Flagstaff Hill.  The blazed trees or stone cairns marked the places where the surveyors took their observations i.e. determined by instruments exactly where they were. CT Madigan in 1939 and Len Beadell in the 1950s and 1960s blazed trees to mark their passing. Today's explorers and adventurers would use GPS. Historical enthusiasts and 4-wheel drive clubs have traced many of the explorers' routes by locating their blazed trees and cairns, after careful reading of their diaries and reports.

A decision was made nationally in the 1980s by the National Trust to only include living trees in their registers of significant trees. This has meant that many trees of significance in exploration have not been listed: these are being held 'in reserve for more appropriate listing as either historic monuments or archaeological relics'.  The National Trust did however list Burke's tree at Innamincka.

Further reading:

Gillen, Jake, Trees of significance in South Australia taken from the Register of Significant trees Adelaide, National Trust of South Australia, 1986.

Moore, Rick, Cones of stone, Adelaide: John McDouall Stuart Society, [2004].

Porter, John, "The jubilee 150 surveyor-explorer expeditions", South Australian geographical journal volume 90, 1990, pages 32-49.

Stubbs, BJ,  "The Investigator tree: eighteenth century inscriptions or twentieth century misinterpretations", Royal Historical Society of Queensland Journal, volume 16, Number 3, 1996, pages93-107.  You can also access this article at http://www.burkeshirecouncil.com/sweers_island/investigator_tree.htm