The complexity and location of the Large Aperture Seismic Array (LASA) pose difficult problems for the system designer. This paper discusses the features of the array, the problems presented, and the solutions chosen to meet them. The location of an array such as LASA is dictated by seismic considerations. Those criteria which affect system design and their implications are discussed with regard to several major components of the system, the signal collection, the communications, the signal recording, and the array control. In the case of the Montana LASA, only a very short time was available for its implementation. This had a major influence on component choice and system design, but did not compromise either the performance or reliability of the system.