In a recent press release (link below), the USPTO announced that it has designated its most recent Patent and Trademark Depository Library (PTDL). The University of Baltimore School of Law Library, the newest PTDL, opened to the public yesterday to provide “access to intellectual property information including more than 7 million patents and over 4 million active or pending trademark registrations, as well as other related information in various print and electronic media to support the diverse intellectual property needs of the public” along with the other designated PTDLs. According to the USPTO press release, the “USPTO's patent and trademark depository library program is a nationwide network of public, state and academic libraries authorized to disseminate patent and trademark information and to support inventors, intellectual property attorneys and agents, business people, researchers, entrepreneurs, students, historians and the general public who are not able to come to USPTO's offices in Alexandria, Va.” In addition to being accessible free of charge, the PTDLs “include assistance in accessing and using patent and trademark documents, training on USPTO databases, obtaining access to the USPTO Web site, and hosting public seminars on intellectual property topics for novice and experienced innovators.” There are now a total of 85 libraries located in almost every state, the District of Columbia, and Puerto Rico.

USPTO Press Release: LINK
USPTO PTDL Program Webpage: LINK
Cumulative PTDL List (Hyperlinked): LINK
University of Baltimore School of Law Library Webpage: LINK