Pennsylvania officials denied the elk's re-entry from West Virginia because of concerns that it could be infected with chronic wasting disease.
That disease can't be diagnosed with testing, but tests for other diseases were all negative.
The West Virginia Division of Natural Resources says Elvis is still being monitored but appears to be in excellent health.
Center biologist Gene Thorn tells WTOV-TV (http://bit.ly/KOvS11) that Elvis was quarantined for 90 days before being moved into the breeding herd.
He says Elvis is big for his age and will add genetic diversity to the herd.
Information from: WTOV-TV, http://www.wtov9.com