Looping south from Interstate 90 for 11.6 miles, the Rapid City business route overlays former alignments of U.S. 14, U.S. 16 and SD 79. The business loop begins at Exit 52 at Black Hawk and runs south along Sturgis Road (old U.S. 14) to Main Street in west Rapid City. This stretch is state maintained to Chicago Street and designated, but not signed, as SD 231. Signs at Chicago Street reference an unnumbered truck route in lieu of SD 231 shielding.

Main Street comprises a five-lane commercial boulevard east to the outskirts of Downtown, where it splits with St. Joseph Street eastbound to form a one-way couplet through the business district. SD 231 parallels Business Loop I-90 to the north along Chicago Street, a divided arterial leading east to unsigned SD 445 and Omaha Street. SD 445, signed as an unnumbered truck route as well, lines Omaha Street east to SD 44, which intersects Main Street via Mountain View Road and parallels Business Loop I-90 eastward along Omaha Street.

The city maintained portion of Business Loop I-90 turns north from Main and St. Joseph Streets onto East Boulevard to cross paths with SD 44 (Omaha Street) once more. East Boulevard (old U.S. 16) crosses Rapid Creek and transitions to North Street as Business Loop I-90 curves east along a commercial strip to Northgate Shopping Center and Campbell Street. The remainder of the route arcs northeast by newer development and big box retail to conclude at a single point urban interchange (Exit 60) with I-90 & U.S. 14.

The west end of Business Loop I-90 originally tied into I-90 at a split interchange north of Black Hawk. Road work underway between March 2008 and January 2009 realigned the I-90 mainline and added a new diamond interchange at Black Hawk to replace the older ramps to the north. This shortened Business Loop I-90 slightly, with the route shifting east from Sturgis Road to Interstate 90 via Peaceful Pines Road.

Business Loop I-90 East
Business Loop I-90 (St. Joseph Street) east at 6th Street in Downtown Rapid City. 08/20/14
5th Street winds north from U.S. 16 Bypass and the south Rapid City suburbs to intersect Business Loop I-90 south of Memorial Park and the convention center. 08/20/14
Eastbound St. Joseph Street at 3rd Street and the Pennington County Courthouse. 08/20/14
Business Loop I-90 turns northward from St. Joseph Street onto East Boulevard. 08/20/14
St. Joseph Street continues east beyond the split with Business Loop I-90 to combine with Main Street at the South Dakota School of Mines & Technology. St. Joseph Street south to Minnesota Street is part of former SD 79. 08/20/14
Business Loop I-90 West
Departing from Interstate 90 westbound, Business Loop I-90 joins North Street south from a SPUI. 08/20/14
Business Loop I-90 west seamlessly transitions from North Street to East Boulevard. 08/12/13
New York Street intersects East Boulevard beside Time Square Plaza shopping center 08/12/13
Drivers along East Boulevard cross Rapid Creek ahead of SD 44 (Omaha Street). SD 44 runs along the north side of Downtown and Memorial Park. Rushmore Plaza Civic Center lies north of Rapid Creek via 5th Street from SD 44 west. 08/12/13
SD 44 provides a truck route bypass of Downtown Rapid City as part of an overall truck route west to Chicago Street (SD 231) and Deadwood Avenue (SD 445). 08/12/13
Business Loop I-90 continues south from SD 44 (Omaha Street) to Main Street. SD 44 joins Rapid City with U.S. 385 to the west and Rapid City Regional Airport (RAP) to the east. 08/12/13
Leading away from East Boulevard on Main Street west. 08/20/14
This section of 3rd Street travels just three blocks from adjacent St. Joseph Street and the Pennington County Courthouse to SD 44 (Omaha Street). 08/20/14
A reassurance marker for Business Loop I-90 appears at the Main Street intersection with 5th Street. 5th Street heads north to the convention center and Memorial Park. 08/20/14
Main Street westbound at 6th Street by Main Street Square park. 08/20/14
Business Loop I-90 (Main Street) west at 7th Street. 08/22/14
U.S. 16 follows Mt. Rushmore Road south from Omaha Street (SD 44) two blocks to intersect Business Loop I-90. The US route ends at I-90/190 to the north. South out of Rapid City, U.S. 16 travels a four lane divided highway to Rockerville and SD 40 near Keystone and Mt. Rushmore National Memorial. 08/22/14

Photo Credits:

08/12/13, 08/20/14, 08/22/14 by AARoads

Connect with:
Interstate 90
U.S. 16

Page Updated 07-19-2016.

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