1989

This article appeared in the March 1989 Bicycle Guide magazine.  It sure appears to be the later Boulder design but I am not sure if it is the same 

1991

September 1991 BIKE magazine (German) review:

March and October 1991 bike ads:

November 1991 prototype with Action Tec and Rock Shox suspension:

1992

January 1992 Boulder brake press release:

1993

September 1993 Boulder Defiant Ad: 

Former Boulder designer introduces his own line of bikes in October 1993: