Inmates at a washington penitentiary are helping to raise endangered frogs as part of an effort to revive the population. The inmates have had much higher success rates at raising the animals than other sites, including the woodland park zoo. Their success is partly attributed how much more time the inmates are able to devote to the project than the other locations.
Allowing prisons to be involved in environmental projects seems like such a good idea to me for so many different reasons, I don't know where to start - inmate self esteem, use of state funds / ROI on the costs of prison, job training while in prison, etc etc etc.