Your Snow Leopard ISO cannot just be copied to a USB stick like a modern macOS installer. Snow Leopard uses an ancient bootloader.
For those needing an ISO image today, several community-driven archives host verified retail images: mac os x snow leopard 10.6 8 iso download
Mac OS X Snow Leopard 10.6.8 is the eighth and final major release of Mac OS X 10.6. It was released on June 25, 2010, and brought several significant updates, including: Your Snow Leopard ISO cannot just be copied
For many Apple enthusiasts, Mac OS X Snow Leopard 10.6.8 remains the "gold standard" of operating systems due to its legendary stability and performance It was released on June 25, 2010, and
. Even years later, enthusiasts and professionals continue to use Snow Leopard for its legendary reliability and its ability to run legacy software via , a tool that allowed PowerPC apps to run on Intel chips.