Soil organic carbon (SOC) in grasslands plays a central role in global carbon cycling, yet how long-term grazing intensity (GI) and soil texture interact to affect SOC fractions remains unclear. We evaluated SOC partitioning into particulate organic matter carbon (POM-C) and mineral-associated organic matter carbon (MAOM-C) after more than 80 years of cattle grazing in a semiarid mixed-grass prairie in South Dakota. Soils (0-30 cm) were sampled across six pastures managed at high, medium, and low grazing intensities and stratified by texture (clay loam vs. silty clay). Bayesian mixed-effects models accounting for pasture-level variation revealed that while GI did not significantly affect MAOM-C stocks, surface POM-C (0-7.5 cm) was significantly higher under high and medium grazing in clay loam soils, with no significant grazing effects observed in silty clay soils. Across depths, POM:MAOM ratios were elevated in coarser soils and under heavier grazing, suggesting greater POM-C accrual but also increased vulnerability to loss. Correlations showed only modest coupling (r approximate to 0.3, p < 0.001) between POM-C and MAOM-C, underscoring that these pools respond to distinct processes. Overall, our findings indicate that soil texture strongly modulates grazing effects on carbon fractions, with coarse-textured soils favoring POM accumulation and finer soils maintaining more stable MAOM stocks. These results highlight the importance of accounting for soil physical context when evaluating grazing as a tool for enhancing grassland carbon sequestration.