This may (or may not) have something to do with where the song might have come from. What About My 40 Acres & A Mule? by Gerene L. Freeman It certainly accounts for thousands of hits on any search containing "mule" in any form or combination.On the other hand, mules were used as military pack animals up through and including WWII, so there could be many other possibilities. Everyone loved them(?).
I have checked a few of the sites for the group "Gov't Mule" with the thought that they might have named themselves for a song that they performed. No luck. The do have one song called "Mule" in their repertoir, but it is clearly not the one wanted.
An oldie, called Whoa Mule deals with the right subject matter - a mule causing trouble, except that there is no mention of the subject being a "government mule."
A search for "Bob Marshall Wilderness" turns up a number of "outfitters" and "lodges." If the requestor was there with a group, or knows the name of a lodge near where he(?) camped? Maybe the next time someone is there, they can look for a song book? :>). In the "Bob Marshall Wilderness" returns, I found a "personal site" on someone's trip there - impressive pictures, but no specific i.d. or contact information, except that he(?) was a member of the umass outing club and says he(?) likes music of all kinds. The University of Massachusetts Outing Club has a site, with contact link to the faculty advisor, at umas outing. Maybe they have a song book(?)
Do we have a category for "Outing Club Songs?"
All of this is "unhelpful" for the present search. I'm sure, though, that I have seen/heard something like what is being requested. Most of our music "holdings" are pretty well indexed, and it doesn't turn up there, so I'm looking in "miscellaneous" now.
Library of Congress searches turn up 40 Acres and a Plow, undated recording by an unknown (to me) group which unfortunately has the same name as a popular website - and the song title itself is the "title" or "name" of several hundred sites/postings.
The LOC listing shows 40 Acres and a Plow composed by B. Sigles; Phil Hurt; arranged by B. Sigles. Performed by Sound Experience.
One search hit on a news release by the "Houston Chronicle, May 1999, credits a song titled 40 acres... to "local band" called Caedmon's Call, a "folk-rock band with Christian roots." This would have been far too recent to be remembered as an "oldie." None of the listed members of this group match the LOC information.
The same title was also used - very recently - by a Spike something or other - but is also too recent, and is too full of obsenities to be memorable (personal opinion.). Approximately the first 300 Google hits for the title +lyric are on this one - or mostly so.
A couple of groups, none familiar to me, have recorded Francis the Talking Mule - which certainly qualifies as a song about government mule that got into a lot of trouble, but I'm unable to find lyrics. Too many ads for DVD's of the old movies. (Google search +title +lyric finds that a "lyric productions" is all over the web in oldies DVD remakes).
John