Thank you for your response, I am often in areas where cell service as well as internet access is impossible for extended periods of time. I would like to keep copies of distros available on a separate hard drive for those times.G'day Jay, and Welcome to linux.org
Make the usb non bootable. Just load the iso to the usb without using a program to make it bootable.
You can then load that bunch of files to another usb at a later time.
Why would you not be able to simply download that iso at a later time...?....or have I misunderstood ?