Tailings are the waste product produced by mining operations, containing both benign and contaminated materials. Modern policy requires mines to ensure that tailings are placed in tailings management facilities, however historic mines often left tailings exposed and unconstrained. Improperly managed tailings pose a risk to the local environment, and contaminants may be transported via wind or streams to affect a large area. Cleanup of these sites is important however it is expensive and time consuming. The Canadian Mine Tailings Inventory (CMTI) aims to aggregate tailings data from across the country, making it easier to assess risks from individual sites or perform regional assessments. The inventory is part of a larger initiative to treat mine tailings as a secondary resource of minerals, especially critical minerals, providing further incentive to revisit abandoned tailings and offset remediation costs. The CMTI is a compilation of mine and tailings records from multiple sources, including large databases like the Orphaned and Abandoned Mines database and provincial inventories, such as Ontario’s Mineral Inventory. Individual mine tailings disclosure reports are also included, which are mandatory reports released by mines under the Standards of Disclosure for Mineral Projects (National Instrument 43-101). A tailings sampling program is being developed alongside the CMTI, which provides a protocol for collecting and characterizing tailings. This program will be used to obtain more detailed geochemistry data for priority sites. The current database contains over 15 000 sites. Future work will prioritize filling in missing data by performing field work or partnering with other organizations and industry, as well as finalizing its release to the public.