The manuscript "A strontium isoscape of southwestern Australia and progress toward a national strontium isoscape" provides a timely and important contribution to understanding the, terribly under-researched, regional distribution of strontium isotope values in Australia.  The authors present robust geochemical data in a useful and accessible fashion, which should be of wide interest for researchers from a range of fields.  I hope that these authors continue their important work (begun as de Caritat et al. 2022 and de Caritat et al. 2023) to continue mapping these values throughout Australia.

My only minor suggestion is that the authors provide more details of how they tested the Rb level in the samples (detailed in lines 191-194).  This doesn't change the substance of the paper in any way, but provides a useful methodological point for other studies.

• Excellent work, great and useful data and well presented
• 3^rd instalment in series of Sr isotope data around Australia including: de Caritat et al., 2022, 2023
• Provides comprehensive, detailed, high quality data set and publication for a geographical region where very little was previously known.
• Significant and valuable dataset for strontium isoscape work
• Minor question: Figure 3 labelling. Legend says SE Aus, caption northern Australia. Should these both be SW Australia?