The Oklahoma Department of Transportation and Oklahoma State University School of Civil and Environmental Engineering are currently conducting a research program to evaluate options to minimize approach embankment settlement. The research program involves construction of three new bridges on U.S. 177 north of Stillwater, Oklahoma. Five of the six approach embankments/abutment backfills were constructed using different construction materials and methods. The constructed approach embankments include: unclassified borrow (control section), geotextile reinforced wall, controlled low strength material, dynamically compacted granular backfill, and flooded/vibrated granular backfill. The approach embankments/abutment backfills have beeninstrumented to measure earth pressure on the abutment walls, settlement and lateral movement of the approach embankments, and groundwater conditions. The paper documents the design and construction of the CLSM approach embankment and reviews the instrumentation data collected to date.