There were two locations for Thumper’s.

THUMPER’S SOUTH

The original Thumper’s started out at Schlief’s Little City, a polka dance hall in Inver Grove Heights and South Robert Street (7884 Courthouse Blvd.)

Thumper’s South opened on December 14, 1978.

This is apparently Thumper.

Thumper’s South was owned by Mickey Sazenski and managed by Dennis Sazenski.  The actual ownership was in question, so Mickey let the insurance lapse in March 1979 and hoped to reopen in June.  Unclear whether it did.

Thumper’s South became Peabody’s in November 1979.

THUMPER’S NORTH

There was another Thumper’s at 2020 Northdale Blvd. in Coon Rapids, owned by Mickey Sazenski.

David Allan Wright has posted a video of the local band Chameleon at a performance at Thumper’s North on July 15, 1978.

Thumper’s North – photo courtesy Laurie Peterson Buck

Chip Barber’s Thumper’s North Mug!

Thumper’s North Pass posted by Sandra Kenyon

Thumper’s  North later became La Fiesta in 1985.  I only found one reference in the Minneapolis papers in January 1986.

Thumper’s Schedules, January 1979 – courtesy Kim Brandell

Thumper’s North and South Schedules, March 1979, courtesy Sandra Kenyon