In July of 2006, I operated HF from Michigan for the first time in 45 years.  I was 11 years old and held the call WN8AQL the last time I had a QSO from the Marquette county area.  I have now returned to Michigan's Upper Peninsula and spend part of the year operating from our cabin on Pike Lake.
 
Camp is located 20 miles south of Marquette, MI (and Lake Superior) near Gwinn, and a half mile from one leg of an abandon Extremely Low Frequency communications antenna line that was associated with Project ELF.*

  When operating from our cabin in the woods, I use a 30 year old Yaesu FT-757 GX.  The antenna is a north-south 102 foot inverted-V doublet at 35 feet and fed with 300 ohm ladder-line to the homebrew balanced tuner with 1:1 current balun.
 
Joe (AJ8MH)
ex: WPE8EUM, WN8AQL, WB5FCO and WJ5MH
 
*See Project ELF notes and photographs below.

  Project ELF became operational in 1989 and was designed to communicate with deeply-submerged submarines.  It consisted of two transmitter sites, one near Clam Lake in Northern Wisconsin, and the other near Republic. The sites were separated by 145 miles.  (The main transmitter in Michigan was 7 miles southeast of Republic at 3041 County Road FFG.)
 
In Michigan, three antenna lines were used in an area south of Republic, north of Iron Mountain and West of Gwinn.  Two lines were about 14 miles long and one was roughly 28 miles long.  These lines were laid out loosely resembling the letter "F" with the longest line running north-south, and the smaller lines running east-west. 
 
Some research needs to be done to verify this, because the line by camp appears to run north-northeast, north and then north-northwest from its termination point.
 
(Update 2011:  Once I located the transmitter site using satellite images, I was able to trace the antenna lines, and it's clear that the lines seldom ran in a straight line.  They also seemed to have termination "fingers" at the end of each run.  On September 1st, I took my wife and our little dog on a drive to the site.  The gate across the main road was locked, but no "no trespassing" signs were posted, so we walked to the main compound area and took pictures of the abandon site.  I believe the site is still for sale.)
 
(Update 11/14/2011:  In an article by the Associated Press, the Defense Department was offering $400,000 to demolish the installation, so the Humboldt Township community decided to look for ways to reuse the 6.9 acre site and keep the money in the county's coffers.  The township should get title to the property early in 2012 pending completion of the second round of environmental clearances.)

  The antenna line looked like a single power-line mounted on 40-foot wooden poles.  It's been reported that the typical operating frequency was centered around 76 Hz. 
 
The project was closed down in 2004, but some hardware remains.  Mostly just the poles are standing today.  (Update 2008:  Poles have been removed, and I haven't found any other evidence of the antenna system.)
 
You can find additional information on Project ELF throughout the WEB, but a lot of it from anti-nuclear weapons activists involved in a long campaign against what they dubbed a "nuclear war trigger."  John LaForge of Nukewatch helped coordinate the Coalition to Stop Project ELF.*
 
Bonnie Urfer, co-director of Nukewatch said, "I feel relief for the people of the area and the local environment, knowing that ELF's million-point-three watts of electricity will no longer be jolted into the ground, shocking the aquatic life and increasing the threat of leukemia and other cancers."*
 
So far, the fish I've caught seem to be healthy and not abnormally large or disfigured, and I haven't seen any strange creatures roaming the backwoods, although Bigfoot (Sasquatch) has been reported in the area.  (My outhouse is unlocked in case he stops by some evening.)  Also, reports of an underground alien spaceport located in the Upper Peninsula have been greatly exaggerated.
 
 
*Information from The Nuclear Resister, Nr. 135, PROJECT ELF CLOSES dated October, 2004.