  Water fountain objects are generally defined as "evolved stars with low to
intermediate initial mass accompanied by high-velocity molecular jets
detectable in the 22.235 GHz H$_2$O maser line". They are the key objects of
understanding the morphological transitions of circumstellar envelopes during
the post asymptotic giant branch phase. Masers are useful tools to trace the
kinematic environments of the circumstellar envelopes. In this letter we report
the discovery of exceptionally uncommon excited-state hydroxyl (ex-OH) masers
at 4660 and 6031 MHz toward the water fountain source IRAS 18460-0151. These
are the brightest ex-OH masers discovered in late-type objects to date. To the
best of our knowledge, prior to the current work, no evolved stellar object has
been observed in the 4660 MHz ex-OH maser line. The ground-state hydroxyl
(g-OH) masers at 1612 and 1665 MHz are also observed. The velocity components
of the 4660 MHz ex-OH maser line and the much weaker 1665 MHz g-OH maser line
all can be seen in the 1612 MHz g-OH maser line profile. The blue-shifted
components of the three masers are more intense than the red-shifted ones, in
contrast to the ex-OH maser line at 6031 MHz. The relevance of the behaviors of
the ex-OH masers to the circumstellar environments is unclear.
