Surface mining operations used to access the Athabasca Oil Sands deposits currently affect 150 km2 around Fort McMurray, northeastern Alberta. Following mining, land reclamation entails the re-establishment of functioning ecosystems through the creation of soil-like profiles using salvaged soil materials and mining by-products. The overall objective of this research is to assess how different reclamation practices influence organic matter quality in reconstructed soils as compared to undisturbed forested soils found in the Oil Sands region. Soil samples (0-10 cm) were taken from replicated undisturbed and reclaimed sites chosen from the network of Long Term Soil and Vegetation Monitoring Plots established in the Fort McMurray area. The distribution of carbon among labile (low-density) and recalcitrant (acid-insoluble) organic matter pools was quantified using a combination of density, particle-size, and acid hydrolysis separation techniques. Chemical composition of the low-density fractions was characterized using ramped-cross-polarization (RAMP-CP) 13C Nuclear Magnetic Resonance (NMR) on a Bruker Avance 400 spectrometer. Spectral divisions were assigned based on local minima of the spectra to differentiate among alkyl, O-alkyl, aromatic, phenolic, and carbonyl carbons. Integrated areas of spectral regions were ordered by non-metric multidimensional scaling (NMS). The multiple response permutations procedure (MRPP) was used to compare the distance among points. Undisturbed and reclaimed soils showed significant differences in organic matter composition, although the undisturbed soils presented greater variability than the reclaimed soils. Within the reclaimed soils, the alkyl/O-alkyl ratio increased with increasing time since reclamation. Finally, while the low-density fraction (as % total soil weight) displayed a positive correlation with the O-alkyl carbon content in the undisturbed soils, it correlated with the alkyl carbon in the reclaimed soils.