From the west side of the Frisco line heading south from Sheffield Junction, the Rock Island departs at Leeds Junction (MP 288.3), climbing up and swinging over the Frisco and the MoPac, and then the KCS, on bridges heading southeast, single track, "Voice Control" (Rules 700 to 715), maximum speed 35 mph, past a 240 ft. spur for Universal Trailer Co. (MP 283.4), south past the 4,560 ft. siding and 1,400 ft. spur at Raytown (MP 282.7), southeast, just west of due south, past Yale (MP 277.5), southeast, past a 2,400 ft. spur at South Lee (MP 272.0), south-southeast, just to the west of the MoPac line, past a 1,040 ft. spur at Greenwood (MP 268.7), the 3,310 ft. siding and 2,680 ft. spur at Pleasant Hill (MP 262.9), and the flat crossing (20 mph on the crossing) with the MoPac line to the south at MoPac Crossing (MP 262.5), still west of the MoPac line east.
The line turns east-southeast, past Wingate (MP 257.5), Hadsell (MP 253.0), a bridge over an MKT line, a 320 ft. spur at Medford (MP 245.4), Denton (MP 240.5), and the 3,380 ft. siding and 920 ft. spur at Chilhowee (MP 235.4), where the MKT comes alongside to the north, turning just south of due east, past Post Oak (MP 229.6), just north of due east, past the 640 ft. spur at Leeton (MP 227.0), just south of due east, with the MKT line edging away, past New Castle, Bowen (MP 220.8), the 3,660 ft. siding and 2,400 ft. spur at Windsor (MP 216.3), where there is a crossing with another MKT line, Brandon (MP 211.0), a 2,120 ft. spur at Ionia (MP 205.4), a 260 ft. spur at Hunt Spur (MP 202.6), May, a flat crossing with a MoPAc line, and a 960 ft. spur at Cole Camp (MP 198.8), turning east-southeast, south-southeast past Crest (MP 194.3), and east, past Morgan (MP 190.0) and the 2,433 ft. siding and 1,367 ft. spur at Stover (MP 185.9).
A shortline trails in on the north side at the 3,600 ft. siding and 3,000 ft. spur at Versailles (MP 177.0), where a MoPac branch crosses, and the line heads curvily east-southeast, past Marvin (MP 171.9) and Barnett (MP 166.2), to the yard at Eldon (MP 159.9), where a MoPac line crosses and the maximum speed drops to 25 mph, turning curvily east, past Etterville (MP 133.7), a 640 ft. spur at Eugene (MP 149.5), the 5,270 ft. siding at Henley (MP 144.7), where a shortline trails in on the north side, bridging over the Osage River, with a 20 mph speed limit on bridge 1433 (MP 143.3), to Hoecker (MP 140.5), and becoming very curvy as it leaves that river behind, past a 2,400 ft. spur at Meta (MP 134.6), Tunnel 2, Koeltztown (MP 129.3), the 3,580 ft. siding and 1,000 ft. spur at Argyle (MP 125.1), Tunnel 1, a 960 ft. spur at Freeburg (MP 118.2), Gascondy (MP 114.4), and Summerfield (MP 111.0).
The line turns curvily east-northeast, past the 2,050 ft. siding and 2,560 ft. spur at Belle (MP 105.2), the 3,710 ft. siding and 2,000 ft. spur at Bland (MP 100.1), a 600 ft. spur at Ellis (MP 97.3), Canaan (MP 95.6), the 2,005 ft. siding and 1,742 ft. spur at Owensville (MP 91.5), the 2,409 ft. siding and 1,074 ft. spur at Rosebud (MP 84.7), and the 2,200 ft. siding and 1,560 ft. spur at Gerald (MP 80.7), curvily east, past the 3,710 ft. siding and Leslie (MP 74.0), and a 600 ft. spur at Beaufort (MP 71.6), northeast, past a 184 ft. spur at Jeffriesburg (MP 64.9), curvily east, past the 2,978 ft. siding and 5,729 ft. spur at Union (MP 59.5) and Hills (MP 55.2), and curvily north-northeast, past a 720 ft. spur at Villa Ridge (MP 51.2), a bridge carrying the MoPac main line overhead, and the 2,000 ft. siding and 600 ft. spur at Labadie (MP 46.0).
A spur to the Labadie Power Plant is served by means of a 240 ft. spur on the north side at Union Electric (MP 44.5), and the line turns east-northeast, north-northeast, past a 720 ft. spur at St. Albans (MP 39.9), where the Missouri River comes alongside to the north, and just north of due east, past the 6,600 ft. siding at Centaur (MP 33.4), where the river turns away, Monarch, a 3,200 ft. spur at Air Park (MP 30.0), a 160 ft. spur on the north side at Helwig Brothers (MP 28.6), a 1,000 ft. spur at Chesterfield (MP 26.8), a 2,000 ft. spur on the north side at City of St. Louis Water Works (MP 24.2), Hine (MP 23.6), and a 600 ft. spur on the north side at St. Louis County Water Works (MP 23.5), turning north past a junction with a MoPac line on the east side, and Creve Couer.
The line turns east-northeast, past a spur on the south side to Dripping Springs, and the 2,000 ft. siding at Vigus (MP 18.0), where there is an industrial track on the north side, southeast, past industrial tracks on the south side at Maryland Heights, and Clayburn, and east, past the 3,550 ft. siding and yard at Lackland (MP 12.8), to the junction at Elmwood Park, where passenger trains once headed away south towards St. Louis Union Station, while freights continued east.