Jennifer Foster is an equestrian advocate who heads a small group called, if I am not mistaken, People for Public Lands. This group seems to be misnamed, taking extremist positions in support of Foster's vision of "Multiple Use", which includes greater resource extraction and promoting high impact uses of the public's land.
Foster intervened on behalf of a woman who had a long-standing occupancy trespass in the Mojave National Preserve, disputing surveys which showed that the parcel in question is government land. The woman was recently relocated in an agreement with the National Preserve.
I have spoken with Jennifer Foster, and found her to be extremist, irrational, and totally intractable.