Abstract: We report observations of the asteroid 4 Vesta in the L' (3.8 micron) and M' (4.7 micron) wavelength bands. We observed on UT dates April 30 and May 1, 2007, using the Clio infrared camera on the MMT telescope with the adaptive secondary AO system in natural guide-star mode. Our observations are the first to resolve Vesta at these wavelenghts, and we have obtained resolution similar to that of visible-light images made with HST. Given the 5.342 hour rotation period of Vesta, our data give nearly full longitudinal coverage. Painstaking image processing, including maximum-entropy deconvolution, has produced excellent results. Correlation of our images with known topographic information, and mineralogical analysis in the light of previous resolved observations at other wavelengths, are works in progress.