We developed a framework for characterizing an institution's quantitative skills/reasoning support ecosystem to consider how various activities contribute to student success in areas connected to students' quantitative preparation. Through discussions with faculty and staff stakeholders at eight selective small liberal arts colleges, we established that the quantitative skills/reasoning support ecosystem at these institutions consists of four domains: bridge programs with a quantitative component, assessment of readiness, curricular on-ramps, and supplementary support for courses that require quantitative skills/reasoning. The framework includes questions about each domain that can be used by stakeholders in different institutional positions to reflect on existing efforts to support student success in quantitative disciplines and identify opportunities to align or change their institutional quantitative skills/quantitative reasoning support systems to better meet student needs.