I typed this up in another forum and saved it for reference. It doesn't cover every spot, but I think it will give you a good idea of where to go. To summarize it, I would say that the best places to go in a day are:
1. Kirkwood, Webster, and Maplewood, MO
2. Madison, IL
3. Downtown St. Louis and the arch (the arch is mornings for lighting, while the rest of the area is good anytime)
4. Manufacturers Railway (runs in the morning)
I go into more detail in this post:
Near the City:
Most of the rail lines converge in UP's 12th Street yard near downtown St. Louis, also the site of Union Station. There is lots of traffic, and it really isn't in a bad area. If you stay near the yard, the MacArthur bridge, and the riverfront area, you should be fine.
Many of the trains stop in the yard as they are recrewed before heading on their way. Many bridges, including 14th street, are great places to take in the action. Gratiot Street, 7th street, and Choteau Ave. are also great places.
The UP Jefferson City Subdivision and BNSF's Cuba Subdivision split at the west end of the yard, and near Kingshighway and Manchester road, the two lines run along side of each other. The east side of the yard is way more confusing as the two main routes diverge. Much of the traffic, including most of the UP traffic and Amtrak trains, take the MacArthur bridge over to the Illinois side. One move that is always a must see is the Alton and Southern transfer, using one of the road's GP38s and a pair of EMD switchers. It heads east to the A&S's Gateway Yard anywhere from 2-5 pm, and I believe it runs almost daily. Another set of bridges cross over the roads just east of the yard. These bridges support all BNSF trains, as well as Amtrak trains that turn on the wye. Small UP trains and light engine moves also use the bridges to access the Lesperance Street Yard.
North of the yard, at the St. Louis riverfront (and underneath the Arch), the TRRA operates a single track from the 12th street yard. The tracks cross through 2 tunnels under the arch and then duck under the Eads bridge at Laclede's Landing. BNSF mostly uses this line, although TRRA transfers to the Manufacturers Railway also use this trackage. Occasionally, UP and Amtrak trains can be seen.
South of downtown, UP's Lesperance Street yard is located near the 12th street yard, but it probably isn't worth your time. The yard is usually quiet, with dozens of 4 axle EMDs resting at the tower. Occasionally they will make transfer runs, switch the yard, or head to the 12th street yard.
The Manufacturers Railway, located at the foot of Arsenal Street, is another interesting operation. The railroad in its current state is on borrowed time, but there still is a chance you will see a green MP15 shoving up the grade to the historic AB brewery. This job runs in the mornings, with the crew on duty at 7 am. Usually between 7:30 and 8 they will make their first run up to the brewery. Occasionally they will make a transfer to the Lesperence Street Yard. Take HWY 55 or Broadway south and you can't miss the brewery. The Manny's enginehouse is just east of the brewery.
On the Illinois Side, Gateway Yard always has lots of action, but isn't in a great location. I personally have never had a problem there, but I don't recommend it to someone who isn't familiar with the area. I will direct you to this link to read more about the yard:
http://www.railroadforums.com/forum/...ad.php?t=17499
Granite City and Mitchell also are great places on the Illinois side. The TRRA yard in Madison is always busy and always hosts a variety of locomotives from most of the railroads in the area, including TRRA SDs and GP38-3s. Much of the time there is a trio of SDs pushing trains over the hump, and the Geeps go out on local switching and transfer duties. Near the yard, the Merchants bridge crosses the Mississippi River, and that can provide many good photo locations.
North of the yard, the area gets complex. The TRRA usually runs trains into the steel mill in Granite City daily, and the afternoon is always a good time to catch the runs. At WR Junction in Granite City, two major sets of lines come together, and it can be a busy place at times. Lenox Tower in Mitchell (yes, it actually is a manned tower) is where the 3 sets of tracks extending north from WR meet up with some A&S tracks. All of the tracks then break up at this location. The KCS's Schnider National intermodal train (IVNKC) can usually be seen in the mornings from 9-noon.
If you are in the Madison/Granite City area, check out Tri City Port on nearby route 3. It is in an old army base, and it hosts a nice selection of power that is accessible. Don't expect to see anything moving though.
From the City:
Dupo, IL, and south on the UP's Chester Sub is one of my favorite places to railfan. The Dupo intermodal yard is constantly busy with all types of trains. The Chester sub hosts heavy traffic (35-45 trains daily) and train speeds are high. Bluff Road runs along the entire length of the line from Columbia to Modoc, so chasing is possible (albeit challenging). Plus, the line features a pleasant bucolic feeling and is very scenic, especially with the bluffs in the background.
The UP Jefferson City sub runs from St. Louis through many nice and friendly suburbs such as Maplewood, Webster Groves (including the depot at Tuxedo Park), Kirkwood, and Pacific. Kirkwood is always a local favorite because of its traffic, location, and nice photo locations. The depot at the heart of the city is the landmark of the town, and sits at the summit of Kirkwood Hill, a 1.4% grade that brings eastbound coal drags to their knees. About 45 minutes from St. Louis on I-44 is Eureka and the neighboring town of Pacific, which features both the UP and the BNSF's Cuba Subdivision, which handles 6-10 daily trains. UP traffic on the Jefferson City Subdivision consists mostly of coal traffic, although a few manifests and intermodals use the line. Amtrak runs 4 daily trains to Kansas City as well.
The Cuba Sub (mentioned above), is really not a great line to railfan, based on its sporadic traffic patterns. However, the line west of Pacific features several nice photo locations. Lindenwood Yard, located off of I-44 at Shrewsbury, usually has a good selection of power in the yard.
CSX features two lines that run east of Gateway Yard and Rose Lake Yard, and they both are close together through Caseyville. Collinsville is host to the world's largest Ketchup bottle, located conveniently next to the tracks! The route through Collinsville hosts around 12 trains daily, while the route through O' Fallon hosts about 4.
The BNSF's Hannibal Sub is a fun line, but most of the good locations for chasing and pacing are located on highway 79 along the Mississippi River north of Old Monroe, which is a little far from downtown. The line hosts anywhere from 15-35 trains daily.
Like I said, these are only a few of the best places. For mainline action, the UP Jefferson City Sub through Kirkwood and the Chester Sub through Dupo is the best. If you want some shortline action, the Manufacturers Railway is the place to go. If you want a variety, Madison/Granite City is a nice spot. If you have any questions, feel free to ask! I will be more than happy to help.
Edit- I forgot the Museum of Transportation! Historic diesels, steam engines, and electrics. We have the largest collection of steam locomotives in the country, and one of almost every major wheel arrangement. We also have two articulated steam engines (a Big Boy and a Y6a) and a DDA40X. Plus, we have some of the most historic diesels, such as GM demonstrator 103, the second diesel electric locomotive ever made, the first non-articulated passenger diesel, and the CB&Q Silver Charger.