This is from the PDF of BWCA Rules and Regs on the FS website. A link to the full pdf of the pamphlet can be found
here. Non-Quota Self-issuing Permits
Self-issued permits are required year-round for all non-motorized day use visitors, for any motorized day use into Little Vermilion Lake, and for all overnight visitors entering the BWCAW between October 1 and April 30. The self-issuing permit forms are available by mail, at any Superior National Forest office, and at the main BWCAW entry points. No reservation is required, but you will need to carefully follow the self-issuing instructions to fill out the permit. This includes reviewing the rules and regulations on the back of the permit with your entire group. Carry a copy of the permit with you at all times and place a copy in the box at the entry point.