Army Corps of Engineers Frequencies

http://www.usace.army.mil

The Corps have a number of allocated HF SSB frequencies, shown here (all of these are in Kilohertz):

3345.0

5015.0

5327.5

5400.0

5437.5

6020.0

6785.0

6790.0

7357.0

9122.5

11693.5

12070.0

12122.0

12267.0

16077.0

16326.0

16327.4

16358.0

16377.0

16382.0

20659.0

In addition to their own HF frequencies, USACE is a participant in COTHEN (Customs Over the Horizon Enforcement Network). This HF system is used by a number of federal law enforcement and interdiction agencies, including CBP, Coast Guard, the Drug Enforcement Administration, and others. Over the past decade or so, it has become the “go-to” system for nearly any federal agency using the HF spectrum. Here are the latest active COTHEN frequencies, again, all in Kilohertz and using SSB:

5372.0

5905.5

7527.0

8912.0

10242.0

11494.0

12222.0

13312.0

13907.0

14582.0

15867.0

15962.0

18594.0

20890/0

23214.0

24838.5

25350.0

32.4000

38.6900

38.8900

38.9100

40.5100

142.9500

143.0750

143.9750

148.4250

148.6000

148.6625

148.6750

148.7000

148.7125

148.7250

148.7500

149.8250

148.9250

149.5000

149.6750

149.7125

149.7750

149.8000

149.8625

148.9250

150.1750

150.4375

150.5500

150.5875

150.6000

150.6250

150.6750

150.7250

150.7375

150.7500

150.7625

162.0250

162.0500

162.2250

162.2500

162.2750

162.3500

162.6125

163.0000

163.0250

163.0750

163.1250

163.3250

163.4125

163.4250

163.4375

163.5375

163.5625

163.5875

164.0250

164.0500

164.1000

164.1500

164.1750

164.2000

164.3500

164.5000

164.5250

164.7000

164.7250

164.7750

164.9625

164.9875

165.0125

165.0375

165.0625

165.0875

165.1125

165.1625

165.1875

166.2000

166.2250

166.7500

167.9250

168.0000

168.1250

168.2750

168.3250

169.4750

169.5750

170.2000

170.3750

170.6000

171.3875

171.9625

171.9750

173.4125

173.4375

173.4625

173.4875

173.5375

173.5625

173.5875

406.1500

406.1750

406.3750

406.5375

406.5500

406.6250

406.6875

406.8375

406.9375

407.1500

407.2250

407.2375

407.2500

407.2750

407.2875

407.3000

407.3500

407.4250

407.4500

407.4875

407.5000

407.5250

407.5500

407.5625

407.5750

407.9500

408.0500

408.9750

409.0000

409.1500

412.8375         Simplex

412.9250         Simplex

412.9500         Simplex

413.0000         Simplex

413.0250         Simplex

413.0500         Simplex

413.2250         Simplex

413.2375         Simplex

413.2500         Simplex

413.4750         Simplex

413.5125         Simplex

413.5250         Simplex

413.5500         Simplex

413.5625         Simplex

416.4875

416.5375

416.5750

416.6500

416.6750

416.7125

417.5375

417.6500

417.8375

418.0000

Here are some  confirmed uses by various Army CoE locations:
148.9250   N100 - Link to/from CT-MA
162.2250             - The Dalles, OR Dam
163.0000             - The Dalles, OR Dam
163.4375             - The Dalles, OR Dam
168.0000             - The Dalles, OR Dam

171.9250             - Telemetry, IFLOWS – Johnston RI

173.4125   D205 - Bonneville Dam, OR

173.4125   N100 - Vermont Repeater – linked to Ch.01 New England
173.4375   N200 - Cape Cod Canal Repeater

173.4625   N100 - Connecticut Repeater – linked to Ch.01 New England
173.4875   N?     - The Dalles, OR Dam
173.5375   N100 - New England Ch.01 Princeton MA Repeater [Friday Roll Calls – Dam Reports]
417.8375   N?     - The Dalles, OR Dam