OK, here's the final results:

Eight USAC Champions have won features in UMRA:

TONY STEWART
1994 & 1995 USAC National Midget Champion
1995 USAC National Sprint Champion
1995 USAC Silver Crown Champion

UMRA feature wins (11)
7/14/89 Rush Co. Fairgrounds, Rushville, IN
7/18/89 Jefferson Co. Fairgrounds, Madison, IN
9/3/89 Decatur Co. Fairgrounds, Greensburg, IN
9/4/89 Decatur Co. Fairgrounds, Greensburg, IN
7/14/90 Rush Co. Fairgrounds, Rushville, IN
7/17/90 Jefferson Co. Fairgrounds, Madison, IN
8/31/90 Bartholomew Co. Fairgrounds, Columbus, IN
6/29/91 New Paris Speedway, New Paris, IN
7/17/91 Decatur Co. Fairgrounds, Greensburg, IN
7/23/93 Rush Co. Fairgrounds, Rushville, IN
7/4/96 Rush Co. Fairgrounds, Rushville, IN

TATE MARTZ
2004 & 2005 USAC Midwest Ford Focus Champion
2006 USAC Midwest Pavement Ford Focus Champion

UMRA feature wins (6)
8/31/06 Ripley Co. Fairgrounds, Osgood, IN
7/13/07 Bloomington Speedway, Bloomington, IN
7/20/07 Gas City I-69 Speedway, Gas City, IN
8/17/07 Vermillion Co. Speedway, Danville, IL
8/25/07 Mount Lawn Speedway, New Castle, IN
9/22/07 Mount Lawn Speedway, New Castle, IN

MIKE STREICHER
1991 USAC National Midget Champion

UMRA feature wins (2)
11/28/85 Salem Civic Center, Salem, VA
11/29/85 Salem Civic Center, Salem, VA

DUANE "PANCHO" CARTER, JR.
1972 USAC National Midget Champion
1974 & 1976 USAC National Sprint Champion
1978 USAC Champ Dirt Car Champion

UMRA feature wins (1)
7/21/70 Salem, IN (not Salem Speedway)

ROBBY FLOCK
1986, 1989, 1992 & 2002 USAC Western Midget Champion

UMRA feature wins (1)
7/24/81 Rush Co. Fairgrounds, Rushville, IN

BOBBY MICHNOWICZ
2006 USAC California Dirt Ford Focus Champion

UMRA feature wins (1)
7/20/82 Jefferson Co. Fairgrounds, Madison, IN

GARY HOWARD
1989 USAC TQ Midget Champion

UMRA feature wins (1)
7/12/89 Vermilion Co. Raceway, Danville, IL

ROBBIE RAY
2003 USAC Indiana Ford Focus Champion
2005 USAC National Ford Focus Champion

UMRA feature wins (1)
6/30/01 Rush Co. Fairgrounds, Rushville, IN