Stewart Udall Dies At 90

New Mexico – Former Interior Secretary Stewart Udall is being remembered as an inspiration to those fighting to protect the environment.

He died of natural causes Saturday at his Santa Fe home surrounded by his children and their families. He was 90.

President Barack Obama says the former Arizona lawmaker "left an indelible mark on this nation." His time in the Kennedy administration sowed the seeds of the modern environmental movement in the 1960s. In that time, he aggressively promoted an expansion of public lands and helped win enactment of major environmental laws.

Interior Secretary Ken Salazar calls him a "pioneer and visionary in protecting America's natural resources."

New Mexico Gov. Bill Richardson, who ordered flags to be flown at half-staff in Udall's honor, says he was "the father of America's wilderness and national park system."

Udall's family says a memorial will be held later this year in Santa Fe.

Copyright 2010 The Associated Press.