[en] We report new results on the spectroscopy of the 3 ³Σ⁺ electronic state of ³⁹K⁸⁵Rb. The observations are based on resonance-enhanced multiphoton ionization of ultracold KRb molecules starting in vibrational levels v′′ = 18–23 of the a ³Σ⁺ state and ionized via the intermediate 3 ³Σ⁺ state. The a-state ultracold molecules are formed by photoassociation of ultracold ³⁹K and ⁸⁵Rb atoms to the 3(0⁺) state of KRb followed by spontaneous emission. We discuss the potential applications of this state to future experiments, as a pathway for populating the lowest vibrational levels of the a state as well as the X state