Mayer Brown Partner David Narefsky memorized New York’s subway lines at an early age while growing up in Brooklyn. So it’s fitting that this mass transit junkie handled a first-of-its-kind deal to use tax-exempt bonds to finance the expansion of Denver’s commuter rail system.

The bonds will help fund a public-private partnership between Denver’s Regional Transportation District (RTD) and a group of private developers, Denver Transit Partners (DTP). A key part of the project is a route from Union Station downtown to the city’s airport, 20 miles to the east.