Yellow-breasted Chat near the trail entrance. These bird have a distinctive sound. Get to know the sound if you visit in the Spring because it will help you find them. Here are two recording of what the sound like: http://www.allaboutbirds.org/guide/Yellow-breasted_Chat/sounds and http://www.birdweb.org/birdweb/bird/yellow-breasted_chat. The 2nd recording sounds like what I heard.