We have observed a minimum followed by a maximum in the resistivity of the singlet ground state system La1−xPrxSn3. In sufficiently dilute samples (x<.2), resistivity, magneto‐resistance and magnetization measurements indicate that this striking resistance behavior is not attributable to magnetic ordering. Also, this local maximum in the magnetic contribution to the resistivity cannot be explained by a first Born approximation calculation of the inelastic scattering from the crystalline electric field (CEF) levels. The observed behavior is strongly suggestive of ’’Kondo’’ scattering from the excited magnetic CEF levels followed by a precipitative drop in the resistivity ascribable to the thermal deactivation of the excited CEF levels.