Conversation so far:
What did Olmsted help conserve ?
In the 1880s he was active in efforts to conserve the natural wonders of Niagara Falls, threatened with industrialization by the building of electrical power plants.
What is another region he helped conserve ?
designate Yosemite Valley and Mariposa Big Tree Grove as public reserves.
Did he join any association for conservation ?
He was one of the founders of the American Society of Landscape Architects in 1898.
is there any thing other than that interesting in the article ?
Olmsted was also known to oppose park projects on conservationist grounds.
In 1891, Olmsted refused to develop a plan for Presque Isle near Marquette, Michigan.

Question: Why did he refuse to do it ?
Self-contained rewrite: Why did Frederick Law Olmsted refuse to develop a plan for Presque Isle near Marquette, Michigan ?