The Ontario Geological Survey conducted sampling of ~400 peat profiles containing ~1600 individual peat samples, over 208,000 km2 of southeastern, northeastern, and northwestern Ontario, including bogs, fen and swamps and analysis provided information on chemical and physical peat properties and environmental setting. Submitting the concentration of 17 elements (Al, As, C, Ca, Cu, Fe, H, Hg, K, Mg, Mn, N, O, P, Pb, S and Zn) to Redundancy Analysis (RDA) showed that the first axis differentiated bogs from fens and swamps while the second axis differentiated between fens and swamps. RDA 1 was primarily related to geology/surficial deposits and vegetation (tree, moss and herb cover), whereas RDA2 was primarily related to climate and relative cover of trees and shrubs. Principal Response Curve analysis of samples by depth showed that differentiation of the three peatland types occurred down to 300 cm, below which differentiation decreased. A Structural Equation Model revealed the linkages between climate, geology, physical properties and elemental and vegetation composition controlling the peatland type. Further ordinations (non-metric multidimensional scaling or NMDS) presented similar clustering patterns between bog, fen, and swamp peatlands to the RDA analysis. NMDS ordination employed chemical and peat physical properties such as pH, peat type composition, and vegetation cover to show that bogs remain most dissimilar in relation to fens and swamps. Further NMDS ordinations show that at 100 cm and above, Ca and pH appear to be two of the strongest drivers for diverging bogs from fens and swamps.