The Prairie Type 2-6-2 Locomotive No. 2025 was based on the Pennsylvania Railroad’s Class K-4 Pacific locomotive. However, Lionel left off one of the leading truck axles that was on the prototype, which is why their version of this locomotive is classed as a "Prairie." Lionel would not produce a 4-6-2 Pacific locomotive during the post-war years.

This locomotive did not have Magnetraction and early versions of this locomotive came with "Baldwin Discs" that had nickel rims for the driving wheels. These wheels have the "Baldwin" name embossed on them. It has a three position direction unit whose lever is adjustable from the top of the boiler and is located behind the smoke stack. All of the early issues had a No. 2466WX or No. 6466WX tender that had rear deck handrails and staple-end trucks with an electronic coupler and a whistle. Although the four digit number of this engine designates it for use with O27 Gauge track, it will also run on O radius curves. This locomotive is exactly the same as the No. 675 that Lionel sold with their O Gauge sets.

Many of the variations associated with this locomotive involve the keystone that is on the front of the boiler. It should be noted that the boiler front with the keystone are interchangeable. There are six variations:

Variation A: The "2025" number is rubber-stamped on the boiler front keystone in SILVER. Note that this variation is often found with this number worn off. Unpainted aluminum smoke stack and came with a No. 2466W tender that is rubber-stamped "LIONEL LINES." (1947)

Variation B: Identical to Variation A except the "2025" number is heat-stamped on the boiler front keystone. (1947)

Variation C: Identical to Variation A except has a RED and GOLD keystone decal on the boiler front that is numbered "5690". (1947)

Variation D: Identical to Variation C except has a RED and GOLD keystone decal on the boiler front that is numbered "2500". (1947)

Variation E: This variation is similar to Variation A but would boast a redesigned pilot with a simulated front coupler and has a BLACK smoke stack that is considerable smaller than the SILVER aluminum ones. The No. 6466WX tender that came with this variation is sometimes found with a magnetic coupler. (1948-1949)

Variation F: This variation’s most notable feature is that it has spoked drivers instead of the Baldwin discs featured on all of the other variations. Issued during the Korean War when magnetic material was at a premium, this locomotive also has the redesigned pilot with simulated coupler, black steel motor frame sides instead of non-magnetic aluminum, BLACK painted smoke stack that was a separate piece, a sheet metal two axle trailing truck, and a RED and GOLD keystone decal on the boiler front that is numbered "5690". Came with a No. 6466W tender with staple-end trucks that had one magnetic coupler. (1952)