The room temperature observation of quantum mechanical reflections of electrons at an aluminum/gallium arsenide Schottky barrier is reported here. Molecular-beam epitaxy was used to grow an AlAs/GaAs/AlAs double barrier resonant tunneling diode (RTD) followed by an epitaxial in situ grown aluminum/gallium arsenide Schottky barrier. This RTD was used to inject a nearly monoenergetic beam of electrons towards the Schottky barrier. The measured I-V curves show resonances associated with the reflections of electrons at the Schottky interface. Understanding the transport properties of hot electrons at a Schottky barrier may prove important for understanding the physics of metal base transistors and other device structures that employ the use of epitaxial metals.