| A. Skranda OLS |
| A.M. MacKenzie (Woodstock) (1962 - 1982) |
| Abrey, G.B. (PLS) |
| Ansley Clarke Ashman Ltd. |
| Ansley Clarke Ltd. |
| Anton Kikas |
| Archibald Gray & McKay Ltd. |
| Archibald Gray & McKay Ltd. (Goderich Primarily) |
| B. M. Ross, OLS (1950 - 1974) Goderich |
| B. Roger Pickard Surveying |
| B.M. Galloway OLS (partial) |
| Baird & Mucklestone Ltd. OLS |
| Baker & Benedict Surveying Inc. (Woodstock) |
| Becker, G. Surv. Ltd. (1985 - 1989) |
| Bennett & Norgrove Ltd. (1980 - 1991) |
| Bennett Young Limited (1996 - Present) |
| Bennett Young Limited (Bancroft) (2000 - present) |
| Black & O'Connell Limited |
| Black Douglas H (Metro Toronto & Village of Markham) |
| Black, Shoemaker & Robinson |
| Black, Shoemaker, Robinson & Donaldson |
| Boehme & Hume |
| Bowman, Black & Shoemaker |
| Bradbury & Worobec |
| Bradstock, Harold Stanley |
| Brodie & Gardiner OLS |
| Brown & Coggan (Oshawa) (1987 - 1994) |
| Brown & Coggan OLS (Bowmanville) (1987 - 2005) |
| Browne, Cavell & Jackson Ltd. (1850 - 1983) |
| C. Reuben & Sons OLS |
| C. Reuben OLS |
| C.A. MacDonald Surveying Ltd. |
| C.D. Bowman OLS |
| C.D. Royce (1967 - 1995) |
| C.E. Dotterill Limited, OLS |
| C.E. Stinson |
| C.F. Aylesworth Sr & Jr. (1860 - 1940) |
| C.F. Riley OLS |
| C.G. Trivers Ltd. 1976 - 1991 |
| C.R. Lyons OLS |
| C.W. Lloyd 1959 - 1961 Newmarket |
| C.W. Paice (Oxford County Only) (1956 - 1958) |
| Carter Horwood Limited |
| Consoli & Rabideau Surveying Ltd. |
| Coote & Jackson Limited (partial) |
| Coote, Hiley, Jemmett Limited |
| Coote, Jackson & Hiley Limited (partial) |
| Coote, Jackson, Hiley & Jemmett Limited (partial) |
| Culham Surveying (1993 - 2002) |
| Culham Wallace & Davies (1990 - 1993) |
| D. Culbert Ltd. (1998 - Present) Goderich |
| D. H. GALBRAITH |
| D.A. Niven OLS |
| D.H. Black OLS |
| D.J. Howe, OLS |
| D.J. Norgrove |
| D.J. Raymond (1979 - 1984) |
| D.J. Walker OLS |
| D.R. Barcham, OLS (1984 - 1993) |
| D.S. Urso Surveying Ltd. |
| D.W. Dalrymple OLS |
| David Horwood Limited |
| Dennis, J.S. (PLS) |
| Diego Fazio OLS |
| Dino Astri, O.L.S |
| Donald S. McIntosh, OLS |
| Donevan & Fleishmann OLS (1960 - 1990) Cobourg only |
| Donevan & Richards OLS (Cobourg only) |
| Doug Coggan OLS (1984 - 1987) |
| Douglas E. Magee, O.L.S. |
| Drzic, Tom. Ltd. |
| Duncan Ashworth (Brampton) (1981 - 2008) |
| Dunning & Taylor |
| Dunning & Taylor Limited |
| E.L. Burgess OLS (partial) |
| E.P. Bowman OLS |
| E.R. Garden Ltd. |
| Edward C. Carter Surveying Ltd. |
| Eplett & Worobec |
| Ertl Surveyors |
| F. DALE EPLETT |
| F.J. Pearce OLS |
| F.J. Ure (Woodstock) (1887 - 1928) |
| Farncomb |
| Farncomb & Holstead |
| Farncomb & Kirkpatrick |
| Farncomb, Kirkpartick & Stirling |
| Fitzmaurice & Boyer OLS (partial) |
| FKS Land Surveyors |
| Foreht & Gutri, OLS |
| Frazio & Papa Ltd. (-Jan 1984) |
| Friel |
| Friel & Boehme |
| G.V. Consoli Surveying Ltd. |
| GALBRAITH, EPLETT, WOROBEC |
| Gateway Software Testing 1 |
| Gateway Test 2 |
| George H. Bell 1970 - 2003 |
| Gibson, D. (PLS) |
| Gibson, W.S. & Son Ltd. |
| Glenday Surveying In.c |
| Grey, J.C. (PLS) |
| GVS |
| H. Wheeler / Robert Basil Lee (1946 - 1991) |
| H.C. Sewell, OLS |
| H.G. Rose (1932 - 1953) |
| H.H. Gibson & Son (1920 - 1955) |
| H.J. Koester (1969 - 1978) |
| H.L. Mellish Surveying Ltd. |
| H.S. Wilde, OLS |
| Hanning Murphy & Esten |
| Harold Wheeler Associates |
| Harvey & Preston Surveying |
| Haynes, B.J.
|
| Henry Gerrits OLS |
| Herman Van Pelt |
| Holding and Jones Limited |
| Horton & Haynes (Toronto)
|
| Horton Carr & Haynes (Toronto)
|
| Horton Wallace & Davies Ltd (Bowmanville) (1950 - 1990) |
| Horton Wallace & Davies Ltd (Cobourg) (1980 - 1990) |
| Hume & Pickard Surveying Ltd. |
| I.C. McLaren OLS |
| Ivan B. Wallace (1990 - Present) |
| J.A. Smith OLS |
| J.D. Barnes Limited (Simcoe County) |
| J.H. Smith OLS |
| J.K. Young Company Ltd. (1986 - 1995) |
| J.M. & J.S. Leitch, OLS (1915 - 1970) |
| J.N.E. Bradbury, OLS |
| J.T. Ransom (1900 - 1950) |
| James & Wandabense |
| James K. White, O.L.S. |
| James Rubidge & Wandabense |
| James W Nicholson Ltd |
| James W Nicholson Surveying Ltd |
| James W. Nicholson Ltd. |
| James Warren OLS |
| John D. Carter Ltd. |
| John J. Koning OLS |
| John L. Moore Inc. 1959 - 1991, Newmarket |
| John M. Harvey OLS |
| John. E. Jackson OLS (partial) |
| K.F. Lashley OLS (1964 - 1987) |
| Karlins, Al OLS |
| Ken Amer (1973-1984) |
| Kerry Boehme |
| Kisway |
| Koester Bennett Norgrove Ltd. (1978 - 1980) |
| Krcmar Surveying Limited |
| Krcmar Vladimir Ltd. |
| L.G. Bangs OLS |
| L.S. Loginsky, OLS |
| Lawryshyn, R.
|
| Lee, Robert Basil, Ltd. |
| Lloyd & Purcell Ltd. |
| Lloyd Purcell Tomlinson 1960 -1969 Newmarket, King City |
| M.B. Wong, OLS (Toronto) |
| M.D. Brown OLS (1962-1987) |
| M.F. Tulloch Inc. |
| M.J. McAlpine Ltd. (1951 - 1981) |
| M.J. McAlpine Ltd. (1989 - 1993) |
| M.W. Fitzmaurice OLS (partial) |
| MacDonald-Tamblyn Surveying Ltd. |
| Malcolm C. Phillips, OLS |
| Marshal Macklin Monaghan |
| Marshall Macklin Monaghan 1956 - 1983 (Elliot Lake) |
| Marshall Macklin Monaghan Ontario Limited (Markham) |
| Marshall Macklin Monaghan Ontario Limited (Mississauga) |
| Marshall, Macklin & Monaghan Ltd.(partial) |
| Marshall, Macklin, Monaghan (partial) |
| Martin, Blain Surveying Ltd.
|
| McConnell & Jackson |
| McConnell Maughan Ltd (Toronto office) |
| Milesse, L.C. Surv. Ltd. |
| Miller & Urso Surveying Inc. (North Bay) |
| Miller & Urso Surveying Inc. (Sudbury) |
| Miller & Ward Surveying (1982 - 1988) |
| Millesse & Burton / R.I. Burton (1975 - 1990) |
| Monteith & Sutherland Limited |
| Murphy & Esten |
| Murray Ellins, OLS |
| Murray Fraser |
| N.E. Friel OLS |
| N.J. Goebelle |
| N.P. Lyndon OLS (partial) |
| N.W. Moyles, OLS |
| Ophir N. Dzaldov |
| Ostapiak, D.
|
| P.A. Miller Surveying Ltd (1988 - present) |
| P.J. McGuiness (1968 - 1976) |
| P.J. Stringer Surveying Ltd. (1981 - 1998) |
| Passmore, F.F. (PLS) |
| Paul F. Forth, O.L.S., O.L.I.P. |
| Paul H. Torrance, O.L.S. 1983 - 1984 (Elliot Lake) |
| Paul R. Kitchen, OLS |
| Pavlin, Peter
|
| Peter Dewhirst |
| Petzold & Skranda Ltd. |
| Preston Nicholson Harvey Inc |
| R.A. Garden Ltd. |
| R.A.H. Silvera, OLS |
| R.C. Radideau Surveying Ltd. |
| R.E. Morgan |
| R.G. Code OLS |
| R.G. Waterman OLS (parital) |
| R.H. Geyer Surveying Ltd. (1993 - 2000) |
| R.O. Sturdy (partial) |
| R.R. Grant, OLS |
| R.R. Krupowicz, OLS |
| R.R. Smith (Woodstock) (1948 - 1968) |
| R.T. Hanson (1969 - 2006) |
| R.W. Code OLS |
| Rabideau & Czerwinski, OLS (to 2005) |
| Rabideau R.C. Surv. Ltd. |
| Raiend, Valdek, Ltd. |
| Raikes & Bowers Surveying Ltd. |
| Raikes Surveying Ltd. |
| Reuben & Ellins |
| Reuben Reuben Leeper & Ellins |
| Richard A. Preiss |
| Richard A. Preiss Surveying Ltd. |
| Robert Force OLS |
| Robert J. Kingston |
| Robert P. Leeper OLS |
| Rodney C. Raikes Surveying Ltd. |
| Rodney G Reynolds OLS |
| Roger R. Welsman, O.L.S |
| Ron Stewart |
| Roy C. Kirkpatrick, O.L.S |
| Rubidge, W.F.B. (partial) |
| Rudy Mak Surveying Ltd. |
| S. W. Archibald, OLS (1923 - 1998) Huron County (except South Huron) & Bruce County |
| S.J.G. Bird OLS |
| S.M. VOLLICK |
| S.W. Archibald OLS |
| Samuel Bray, P.L.S. |
| Schaeffer & Associates |
| Schaeffer & Dzaldov |
| Schaeffer & Parker |
| Schaeffer & Reinthaler
|
| Scott R. Ray Ltd. |
| Scott, A.B. (PLS) |
| Sneath OLS (partial) |
| Speight & van Nostrand Ltd. |
| Speight van Nostrand Ward Anderson |
| Speight, van Nostrand & Gibson Limited |
| Stephenson, R.T. (partial) |
| T.E. Briggs OLS |
| T.E. Briggs, O.L.S. |
| T.S. Fluke (1986 - 1990) |
| Thistle, W.R. (PLS) |
| Tom Czerwinski Surveying Ltd. |
| Tom Drzic OLS |
| Tulloch & Trivers Ltd. 1991 - 1996 |
| Unwin & Sankey |
| Unwin , Browne & Sankey |
| Unwin, Foster & Proudfoot |
| Unwin, Murphy & Esten Ltd. |
| Ure & Smith (Woodstock) |
| Vanharten Surveying Ltd. |
| Vinklers |
| Vinklers Wallace Ertl Surveyors Ltd. |
| W.A. Baker OLS, W.A. Baker Surveying Inc. (Woodstock) |
| W.D. Smith, OLS |
| W.E. Taylor |
| W.G. Ure (Woodstock) (1920 - 1960) |
| W.G. Wonham, PLS (Ingersoll) (1854 - 1878) |
| W.H. Hall
|
| W.H.L. LaPenotiere PLS |
| W.J. Probert OLS |
| W.M. Fenton
|
| W.S. Winters, OLS |
| W.W. Lorenz Limited (1976 - 1984) |
| Wadsworth & Unwin |
| Wadsworth Unwin & Browne |
| Webb, A.C. (PLS) |
| Wilde, Brodie & Gardiner OLS |
| Wildman Hadfield Ltd. |
| Wildman Rhodes & Assoc. |
| Wildman Rhodes and Assoc. |
| Wildman Stewart Young |
| Wildman W.N. ltd. |
| Wildman, Hadfield, Stewart Ltd. (1967 - 1993) |
| William Galbraith OLS (partial) |
| William J. Beatty, O.L.S., C.L.S. |
| William Jackson OLS |
| Wilson & Bunnell (1910 - 1930) |
| Winarski, P.M. (partial) |
| Winters & Ireson, OLS |
| Winters, Maughan & Glenday, OLS |
| Wm Jackson Surveying Ltd |
| Wm. E. Bennett Surveying Ltd. (1991 - 1995) |
| Wm. F. VanBuskirk, PLS (Woodstock) (1887 - 1890) |
| Wm. M. Davis, PLS (Woodstock) (1885 - 1895) |
| Yates & Purcell Ltd. 1996 -2003 Markham |
| Yates & Yates Limited 1971 - 1996 Markham, Toronto |