Coal surface mining in the northern Great Plains of the United States often produces mining spoils with physical and chemical barriers to successful revegetation, and this has resulted in experiments on reclamation with salvaged soil materials. There is a need to determine changes in soil properties and plant community and productivity decades after reclamation. Experiments were initiated in the mid-1970s by placing wedge-shaped masses of Haplustoll soils over leveled, saline-sodic mine spoils forming 2–5% hillslopes approximately 50 m long at two sites near Zap and Stanton, North Dakota. Seeding treatments at Zap included alfalfa (Medicago sativa L.), crested wheatgrass (CWG, Agropyron cristatum [L.] Gaertn.), smooth bromegrass (SBG, Bromus inermis Leyss.), and Russian wildrye (Psathyrostachy juncea [Fisch.] Nevski); at Stanton, native grasses (two Bouteloua spp.) replaced P. juncea. We examined soil, plant community, and productivity changes 3 decades after the start of the experiments. Leaching of soluble salts in subsoils and mine spoils improved soil quality (SQ). SQ improved more in lower slope areas because more rootzone was occupied by low SQ mine spoil. Initial forage yield patterns showed dependency on hillslope position, reflecting both soil depth effects in lower slope parts of hillslopes and apparent water redistribution effects in middle and upper slope areas. Evidence of SQ improvement over time was inferred by substantial decreases in yield dependency on hillslope position at both sites. The Zap site was grazed more heavily than Stanton, and species composition at Zap was 46% cool-season grasses (CWG greatest) and 40% broadleaves. Stanton had 87% cool-season grasses (SBG greatest) with 3% broadleaves. Leaching of salts was threefold greater at Zap and may have resulted from an abundance of deep-rooted broadleaves. Reclaiming mined land with salvaged soil and revegetation can improve SQ of mine spoil, which our results infer was driven by root growth and establishment of macroporosity.