WHEREAS, modeling by the University of Washington's Institute for Health Metrics and Evaluation estimates that a face covering requirement in Wisconsin could save more than 500 lives by October 1 if 95 percent of Wisconsinites wear a face covering in public;

But where is the research behind this, and what is its provenance. The only document I can find behind the claim is a publication of the said institute (IHME) from 24 June 2020 estimating that 33,059 COVID-19 deaths could be prevented across the United States by October 1 if face-covering rules were adopted within two weeks. It reads:

SEATTLE (June 24, 2020) – In its first projections comparing different actions to control COVID-19 transmission, the Institute for Health Metrics and Evaluation (IHME) at the University of Washington is forecasting nearly 180,000 in the United States will die by October 1.

The forecast shows 179,106 deaths (with a range of 159,497 to 213,715). Those numbers drop to 146,047 (with a range of 140,849 to 153,438), if at least 95 percent of people wear masks in public.

The precise figures given for Wisconsin are:

Wisconsin: 930 (range of 858 to 1,036) / 1,076 (range of 912 to 1,401)

In terms of evidence this seems to be the end of the trail. The document offers no methodology or basis for these predictions, it cites no other document and none can be traced on the National Institutes of Health's website of approved scientific publications Pubmed.