Below is a confusing update.
2013 Update:
The trestle supports which I found at Delombre, US 61, south of St.Francisville, La., were for the South Shore Railroad which was headed north to Jackson or slightly south of Jackson.
A little further south the SSRR merged with the remains of the LN&R near Paloma which was near the Port Hudson Battlefield, west of US 61, south of St. Francisville, so ignore my speculation down the page. I don't get a lot of help and I do the best I can.
When I was chasing the rails which connected the Illinois Central (Yazoo and MS Valley) at Slaughter to St.Francisville (the last emailed ride sent), I had been whizzing down La.964 and noticed what I knew was a rail ROW crossing the road. Not being able to lose concentration on my target, I made a mental note to return and figure this one out. While I had been trying to understand the route of the LR&N Company through St. Francisville, I had seen this mysterious line heading north. Had I found it. Seems I had. Confusing. I know. Here's a big old map with the layout from my Garmin GPS map showing one line going north, possibly the Clinton and Port Hudson which had a spur to Jackson, as expressed on the Old Hickory site. Also shown is the branch I was following from Slaughter to St.Francisville considered a part of the West Feliciana RR branch of the Illinois Central (Yazoo & Mississippi Valley). By the way, those rails are still intact from Slaughter almost to St.Francisville. Asphodel Plantation's website says this: "Two major railroads were built in East Feliciana parish: The Clinton Port Hudson Railroad and the Jackson Port Hudson railroad.
{The "Jackson Port Hudson remains in question. There was a line from the McManus to Jackson called the Jackson RR or something similar.}
Both railroads terminated at the Mississippi River at Port Hudson. The Jackson Port Hudson railroad had a right-of-way through the plantation".
They continue: "The rails going north (below) are shown going into Cole (Asphodel) If they went to Jackson, it is not shown, but I'm betting they did. I suppose there could have been a split at Cole, one set of rails going to Ethel-Clinton, the other going to Jackson but I doubt it. The Jackson branch, the Jackson-Port Hudson RR is mentioned going though the plantation's property. Please mentally change "To Clinton and Jackson" on the map to "To Cole" as that is all I can be sure of right now. I have contacted Asphodel and am awaiting a reply as to whether they know anymore about this line.
Then there's the East Feliciana site that explains more railroad history. Open it in one window and look at the map below to get a handle of what the layout was.
From the IC History Page I gleamed this. 1833 Clinton, LA/Port Hudson Clinton & Port Hudson RR chartered. This railroad played a part in the Civil War battle at Port Hudson and maybe Jackson or Clinton. 1872 Clinton, LA/Port Hickey, LA Clinton & Port Hudson RR extended to Port Hickey. This was another port on the Mississippi up behind Port Hudson. 1889 Clinton, LA/Port Hickey, LA Clinton & Port Hudson RR purchased by Louisville, New Orleans & Texas RR. Here enters the LNO&T into the area. 1889 Clinton, LA/Port Hickey, LA Clinton & Port Hudson abandoned between Ethel and Port Hickey. Ethel and Port Hickey are on the map. Ethel is way up La.19 above Slaughter. Port Hickey is near Port Hudson on the Mississippi River. There are rails shown on the "new" map going to Cole from Port Hudson verified on the Asphodel plantation site. Maybe the Asphodel Plantation site is correct in saying that there were 2 lines. One called the Jackson and Port Hudson and one called the Clinton and Port Hudson. I'm thinking that in the earliest incarnation, maybe, that the Clinton and Port Hudson rails ran alongside La.955 and then went from Ethel to Clinton since 955 is in line with the rails from Ethel to Clinton. Possibly, the rails to Cole were not involved with Ethel, but on a separate ROW to Jackson through the Asphodel Plantation. The Jackson "spur" mentioned on the Old Hickory site was the Jackson Railroad and it ran between Clinton and Jackson and was a whole different deal. So, in 1889, the Clinton and Port Hudson was gone between PH and Ethel on La.19. That left only the route between Ethel and Clinton and Clinton to Jackson. Why does my "modern" Garmin map show the line coming from Port Hudson and going north, crossing the IC (Y&MV) near Delombre and heading north to Cole? The map below shows the Y&MV coming in from Slaughter and the LR&N (Edenborn's ferried RR) coming in from Baton Rouge and going west beneath the Y&MV. If only I had a West Feliciana soil sample map of the same vintage the LR&N mystery would be solved. 1912 
The blue line demonstrates my theory on a direct Clinton to Port Hudson route which the 1912 map shows, after, the Ethel to Port Hinkeyroute was abandoned. Is La.955 occupying the old ROW? 
It seems that I guessed pretty well. This from HERE. This is great reading. "One of the things that helped make Port Hudson the objectof two contending armies was the railroad. It ran in an almoststraight line from Clinton, where the depot stood west of the
business district, to Port Hudson on the Mississippi River, with
a spur to the town of Jackson, La. When the Confederates decided
to create a fortress at the river town, the railroad was used to
move men and supplies. It so became at the same time important
to the Confederates to keep the railroad open, and just as important
to the Federals to shut it down. The original rails were wrought
iron and flat, unlike the more modern I-beam rails familiar to us
today. By the time of the war, the railroad had switched to I-beams,
mostly spiked to original cedar ties."
La.955 sits on the Old Clinton an Port Hudson Railroad.
1892 New Orleans, LA/Memphis, TN Illinois Central acquires Louisville, New Orleans & Texas and places it under Yazoo & Mississippi Valley RR. (The station at Baker was a Y&MV RR station) 1882 Jackson/Yazoo City Yazoo & Mississippi Valley RR incorporated. Railroad is an arm of Illinois Central RR. The IC was now in command. So, what did I find at Delombre and how old was it? And why does Garmin GPS software show it when Garmin doesn't show the LR&N line which lasted until 1940? It is the Port Hudson to Jackson route. It has to have been in existence into the 50's to be on the map software. .jpg)
I first thought I'd found something moderately old. Now I'm thinking I found something very old. I now feel it was the old Jackson and Port Hudson RR but probably the Clinton and Port Hudson? Who knows? You that get my email know what I'm talking about. By the way, I've gotten very lazy and picky. Many of my rides are now sent out as email adventures only. Posting them is just too time consuming. If you want to get them, they are free and private. Go to the guest book and make a private entry and leave just your email if you want. I think I'm the only one in the state that is willing to share his historical railroad adventures with the public, so, if you enjoy that, take advantage of my offer. I'm starting to believe I'm the only one in the state that enjoys these rides except for 2 or 3 old crazies I know and they are off and on (on several levels). Recent news on the Slaughter to Zee tracks. CLICK HERE More bad news from HERE: LOUISIANA - Gloster Southern Railroad Company LLC - To discontinue service over a 32.7-mile line of railroad between milepost 0.0, at Slaughter, LA, and milepost 32.7, at Gloster, MS, in East Feliciana Parish, LA, and Wilkinson and Amite Counties, MS. Effective on January 13, 2010, (STB Docket No. AB-1051X, decided December 8, served December 14, 2009) Misc. Maps The Jackson RR. At Jackson there is a Illinois Central passenger car on the main drag, La. 10. I'm headed there.
1912 MAPS Clinton: I'm headed for Railroad St.
Ethel: Notice the continuation of the line to the southwest. That was the route of the Clinton & Port Hudson Railroad. Ethel is on La.19 due north of Baton Rouge.
And McManus, La.10 and La.19.
And the mystery: What was this (in orange) since it was not the Clinton and Port Hudson? 
Hey, if you can't find any answers it's a great place to ride. Being in a confused condition is a good thing. It makes you aware.