On June 18, 2019, the Accredited Officers of the St. Mary and Milk Rivers (AOs) wrote to the International Joint Commission (IJC) regarding a proposed study of administrative procedural changes and structural options that could potentially improve the access to apportioned waters by each country. They have since provided two documents: Options and Recommendations and St. Mary and Milk River Apportionment Procedures Review – Project Considerations which outline the scope of the study.

Together, these two documents outline a 4-year study that will include detailed hydrological modelling, the consideration of structural and non-structural options, stakeholder and water rights holder engagement, socio-economic impacts and climate change considerations.

On June 28, 2021, the US and Canadian governments wrote a letter of support, supporting the creation of the International St. Mary and Milk Rivers Study.