In the mid 1950’s, Intrusion Prepakt of Cleveland Ohio first patented the soil mixing technique which was also known as the “Mixed In-Place Pile” technique. This technique was later refined by the Japanese in the 1970’s and then re-introduced to the United States in the 1980’s by Geo-Con, Inc. of Pittsburgh, PA. Since this time, soil mixing has become a tool for difficult soil conditions in the Transportation industry and has recently been accepted as a viable ground improvement technique by the Federal Highway Administration. To illustrate recent applications of soil mixing in a variety of conditions, several actual case histories are presented. On a project in Wisconsin in 1997, the multiple auger deep mixing method was successfully used for the first time in the U.S. to construct a permanent retaining/groundwater cutoff wall for a highway. The purpose of this wall was to prevent settlement of the adjacent structures due to a lowering of the groundwater table. This same method was utilized in 1999 on a highway project in Pennsylvania to limit lateral movement of adjacent historic structures and to prevent the loss of support due to unraveling soils. On another project completed this year, a hydraulic soil mixing technique known as jet grouting was utilized to stabilize foundation soils beneath a recently constructed and distressed Mechanically Stabilized Earth (MSE) bridge abutment. Finally, the soil mixing technique is currently being utilized as an areal treatment method to stabilize subsoils beneath large embankment highway fills.