THE Orion molecular cloud, which is obscured by the dust and ionized gas of the Orion nebula, is the nearest example of a giant molecular cloud, Massive stars are actively forming deep in the core of this cloud as a result of large-scale cloud instabilities, fragmentation and gravitational collapse, These young stars will inject a considerable amount of energy back into the surrounding environment through stellar winds and radiation(1), and they are thus expected to exert a major influence on the evolution of the cloud, Here we present a mosaic of ten high-resolution radio maps of the region of the cloud known as OMC-1; the maps were constructed from observations of two ammonia emission lines, which trace the densest regions of the gas while mitigating the obscuring effects of the dust, We find dense filaments of molecular gas with complex motions fanning out more than 0.5 parsec from the central core of the cloud, These filaments appear as long, bead-like chains, consisting of dense clumps of gas that may be the sites of future star formation, The outer sheaths of clumps and the edges of filaments may be heated as a direct result of radiation and outflows from young stars embedded in the central core.