Morris County, NJ has some of the best parks in the state and Lewis Morris is no exception.
I have been hiking these trails for about 20 years. There is a volunteer crew of "park lovers", who along with the county park workers keep the trails in great condition, occasionally adding a new trail or closing an existing one. There are several parking areas on Rt. 124 between Morristown and Mendham, a large parking area by the lake, and a small parking lot off Tempe Wyck Road, just past the entrance to Jockey Hollow. There are a few areas where dogs can take a dip in the streams and although "illegal", many dog owners let their dogs off leash. All the owners I've encountered keep their pets well mannered. During the weekdays, the park is basically empty, but on the weekends, more of the bikers are evident. For the bikers, it's a very nice single track, which from what I understand, it's about a 6 mile loop, with plenty of moderately challenging hills. As far as hiking the trails, they vary from easy to moderate, but I would recommend hiking boots, as it can be rocky. There is a fitness trail and a children's playground. In the winter, there is a spectacular downhill for sleigh riding. Seasonally there is restroom facilities at the lake house, otherwise a port-a-john in one of the parking areas. As the seasons change, the landscape changes and you can enjoy every season in this beautiful park!!!