May 25 (Reuters) - Riversgold Ltd RGL.AX :
* SIGNED CASH & EARN-IN AGREEMENT WITH MAMBA MINERALS LLC FOR ITS GOLD EXPLORATION PORTFOLIO IN SOUTHWEST ALASKA
* MAMBA MINERALS LLC CAN EARN 30% INTEREST THROUGH US$1 MLN CASH PAYMENTS OVER 12 MONTHS
* FIRST EARN-IN OF US$2 MLN SPEND TO SECURE 49% OF PROJECT
* MAMBA MINERALS LLC CAN SPEND US$5 MLN OVER 3 YEARS TO EARN UP TO 70% OF PROJECT
* SECOND EARN-IN OF FURTHER US$3 MLN WILL TAKE MAMBA MINERALS INTEREST TO 70%