A quota entry permit is required for overnight trips in the BWCAW from May 1 through September 30. The quota system regulates how many groups can begin a trip at each entry point each day. There are over 70 entry points to the BWCAW.
Advance entry permit reservations are strongly recommended because there are a limited number of quota entry permits for each entry point. All quota entry permits for summer 2015 become available on a first-come, first-served basis on January 28, 2015.  There is also a very limited permit lottery system that only applies to certain entry points, and primarily relates to motorboat travel in limited areas. The lottery opens for applications on Dec. 16, 2014, and goes through January 13, 2015.  The lottery results are released on January 21. The lottery only includes the following entry points:  D (Fall Lake and Beyond – day use motor), 24 (Fall Lake – both overnight motor and paddle), 25 (Moose Lake – both overnight motor and paddle), F (Moose, Newfound, and Sucker – day use motor), and G (Basswood over Prairie Portage – day use motor).
 
Call us at 218-343-7951 for information on permit availability, and to reserve your entry permit. You can also check permit availability and reserve entry permits at www.recreation.gov.
Groups may only enter the BWCAW on the entry date and through the entry point specified on their entry permit. Permits may only be picked up the day before, or the day of, entry, by the trip leader or alternate trip leader designated on the reservation. Permits are not transferable.
Non-quota self-issued permits are free and required year-round for day use BWCAW visitors, and for all overnight visitors entering the BWCAW between October 1 and April 30.

Source: Boundary Waters Blogger