On the Rock Island District Mississippi River Lock & Dams they had/have simplex UHF HTs on
F1 412.8750
F2 407.5625
F3 408.8750
F4 409.8750
(note I have never heard them, but this is from a friend who worked on the HTs)
The operators at L&D 15 at Rock Island are now using a talkgroup on the Rock Island Arsenal 380 MHz trunked system.
Also a USACOE bomb disposal operator I knew had a VHF HT
F1 163.4125 (127.3) simplex
F2 151.6250 (127.3) simplex