However, his death certificate states that he died of dropsy (edema) on 28 February 1905 and was buried 3 March 1905. Granted, it's only off by one day, but still: it's wrong. Note also that the death certificate spells his given name as Benjamen [sic] rather than Benjamin.
The moral of the story: Just because it's written in stone doesn't mean it's true.
A second moral of the story: Typos can be expensive to fix.
According to New Family Search, Benjamin was born in Llanidloes, Wales, and he has two sets of parents and three mothers, which I highly doubt. Now don't get me wrong, I am not speaking ill of New Family Search, but garbage in garbage out...and there's a lot of garbage floating around. So I take it with a grain of salt. Some of that information was based on personal knowledge of early LDS church members. But as we see from Benjamin's tombstone, sometimes the people responsible for remembering and recording the information don't remember correctly. I'm looking for *documentation* and verification.
According to the 1900 Census, Benjamin and his wife Mary Williams both immigrated in 1848, which at first glance sounds like they were married before they came to America, except for the fact that the 1900 census indicates they married about 1856.  Benjamin was a naturalized citizen by this time, but since he immigrated so early I do not expect his naturalization papers from Utah to provide any details about his specific place of birth. Therefore I haven't even bothered to look for them at this time.
I don't particularly like the 1856 marriage date, because my ancestor Mary Williams was born four years prior to that in Pottsville, [Schuylkill Co.], Pennsylvania on 16 May 1852, according to her death certificate.  This does not surprise me at all. In addition to my own ancestry research, I frequently discover my client's Welsh coal miners wandering around south western Pennsylvania during this time period and from there moving westward as the country opened.
In fact, I came across this interesting quote written by "an Aberdare (Glamorganshire) native, John R. Williams, [who] wrote a message home 10 November 1895, describing coal mining in Pennsylvania" on a fascinating website about Welsh in the Knoxville, Tennessee area:
"The coal trade in the anthracite districts has been extremely dull all through the year, the production overwhelmingly overbalancing the demand. Labor is so plentiful that operators can do just what they please. Pennsylvania is swarming with foreigners -- Poles, Hungarians, Slavish, Swedes, and Italians, etc. -- who are fast driving the English, Welsh, and Scotch miners out of competition. Noticeably, the Poles and Hungarians are a harder-working people and physically stronger men than the English and Welsh. They live much harder and at about half the cost and can stand more and harder work than our countrymen.
"Before the influx of the foreigners I have named into this country, the Welsh had the best show in the mines here, but in consequence of their foolhardy and unreasonable impositions in pretty well everything, they at length became perfectly unmanageable and the operators had no alternative but to send and get whole cargoes of the foreigners I have named, who now practically monopolize the business, and no longer will America hold out a friendly hand to the British miner who must stay at home and do the best he can there or come here and starve. There are in America today and especially in the west, thousands upon thousands of our countrymen who would gladly return to England and Wales if they could only do so, but they cannot find the money". [citing Alan Conway, ed., The Welsh in America: Letters from the Immigrants. (Minneapolis: University of Minnesota Press, 1961), p. 205.]
Although there are actually a very few births recorded for this time frame in Pottsville and other valuable information about this mining community , Mary's birth was not among them. Nor was there a record of the marriage of Williams-Watkins. 
I started exploring LDS church records yesterday to get to the bottom of the mystery. Although it should have been an easy thing to grab Mary Watkins Williams's place of birth from LDS records, she was not found in Logan 4th ward records where I expected her to be based on her death certificate. That is to say that she was not listed in early Logan 1st, 2nd, 3rd, 4th, or 5th ward records, and in an odd twist of fate, the death records from 1911 (when her death certificate says she was in 4th ward) didn't make it to microfilm. It was the one year for which death records were mysteriously not on microfilm. Grrr. So the Williams quest for verification and documentation continues another day.
On a positive note, while researching the Williams family in the Logan LDS records, I came across the Hendersons. The Williams and Hendersons line merge for me with the marriage of James Henderson born 7 Aug 1847 in Haddington, Scotland to Mary Williams referenced above. I was delighted to find the rebaptism of Mary Henderson in 1864 because it provided me not only her place of birth and the names of her parents for my documentation delight, but also her paternal grandfather. More about this in a minute.
1. Headstone for Benjamin Williams, born Nov 10, 1823; died Mar 1 1905, Logan City Cemetery, Logan, Cache Co., Utah. Photocopy of headstone in possession of Heather Henderson as of March 2010.
2. Utah State Department of Health, Certificate of death (Utah Death Certificates 1904-1956), Certificate #31, Benjamin Williams, 28 February 1905; digital image, Family Search, Family Search Record Pilot (www.familysearch.org : accessed March 2010); Utah State Department of Health. Certificate of death. Salt Lake City: Genealogical Society of Utah.
3. 1900 U.S. Census, Cache County, Utah, population schedule, Logan, enumeration district (ED) #79, Sheet 10A, Household #192, Family #202, Benjamin Williams; digital image, Ancestry.com (www.ancestry.com : accessed March 2010); Original data: United States of America, Bureau of the Census. Twelfth Census of the United States, 1900. Washington, D.C.: National Archives and Records Administration, 1900. T623, 1854 rolls.
4. State of Idaho, Department of Health and Welfare, Death Certificate #108033 (copy issued 18 Feb 2010), Mary W. Henderson [died 24 Feb 1938, Pocatello, Bannock Co., Idaho]; Idaho Bureau of Vital Records and Health Statistics, Boise, Idaho.
5. Phillip A. Rice and Jean A. Dellock, Schuylkill County, Pennsylvania, vital records : genealogical and historical miscellany (Laughlintown, Pennsylvania : Southwest Pennsylvania Genealogical Services, c1989-1992) FHL 974.817 H2r v. 1 -3.
6. Miners Journal, Pottsville, Schuylkill Co., Pennsylvania, marriages, deaths, burials, obituaries, 1829-1855 [i.e.1862]; FHL 974.817/P2 V4m.