Cancer cells exhibit high heterogeneity and lineage plasticity, complicating studies of tumorigenesis and development of therapies. Recently, preneoplastic cells, although histologically normal, have been shown to possess high plasticity and early genetic alterations, yet their origins and lineage trajectories remain unclear. Herein, we introduce a lineage-tracing tool integrating genetic barcoding with single-cell RNA sequencing to map preneoplastic esophageal cell lineages. We identified preneoplastic precursor cells (PNPCs) as a distinct progenitor-like population with unique transcriptional profiles and high plasticity, contributing to proliferative and basal cell populations. To enhance lineage mapping, we developed the eXamined Ridge (XR) score, accurately identifying high-plasticity cells.