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Starbursts comma and their powerful galactic-scale outflows comma are an important mode of galaxy evolution. Yet comma owing to their frequently large distances comma we understand little about how these starburst-driven outflows operate. Star formation in these outflows comma previously observed indirectly using spectral decomposition comma and predicted in models comma is an as-yet untapped comma powerful tracer of the complex physics governing these winds. Resolved star formation triggered within a starburst-driven outflow has now been observed for the first time in M82.s prototypical superwind. Deep wide-field imaging has revealed that the wind-induced stellar populations extend in a trail comma well beyond M82.s disk comma displaying an apparent age gradient. This 'trail of breadcrumbs. tantalizingly encodes the history of M82.s outflow. As the first-ever detection of this phenomenon comma M82.s outflow-formed stars present an entirely new lens to study its prototypical outflow comma and a singularly unique opportunity to constrain outflow physics. We propose an efficient comma 12 orbit coordinated WFC3-ACS survey of M82.s trail of star formation in the F475W and F814W filters. This program will allow us to measure the outflow.s star formation history (SFH) within the last 300 Myr. Using this SFH comma we will place the first-ever stringent constraints on (1) the outflow timescale comma (2) the mass outflow history comma and (3) the total amount of stellar material contributed by the outflow to the stellar halo. This exquisite dataset will have tremendous legacy potential as a stellar catalog for spectroscopic follow-up comma and will serve as a case study of this likely ubiquitous comma yet poorly understood comma astrophysical process.