For details of the MiniBooNE beamline, refer to the TDR.
An overview of the MiniBooNE beamline is shown here; it begins in the Main injector tunnel. The MI-8 line transfers protons from the Booster to the Main Injector. Just before the Main Injector, a pulsed switch magnet (851) steers the beam into a separate beam pipe on MiniBooNE event cycles. This first section of the MiniBooNE beamline (up to element 862) is referred to as "MI-10". A mechanical drawing is shown here (PS, jpg). At this point, the beam goes into a 40 meter underground jack pipe and emerges in the MI-12 MiniBooNE beam enclosure. The first part of the MI-12 beam, shown here (PS, jpg) is separately interlocked, and the interlocks must be in place to run beam in the Main Injector. It is referred to as MI-12A. The final section of the beamline is MI-12B, shown here (PS,jpg), includes all the final elements of the beamline as well as the target and horn. It may be accessed while beam is going to the Main Injector.
A TRANSPORT run for the beamline can be found here. It lists the location of each element, the settings of all magnets, the lattice funtions along the beamline, and a fit to the beam at the center of the target.
Shown below is a schematic view of the entire beamline, including the locations of the trim elements and beam instrumentation. Note that it is not quite up to date. The two quads 860A and 860B have been replaced by a single, more powerful quad, and the polarities of 861 and 862 are shown backwards.