There is a single parking area in the northwest corner of the park near the intersection of Hanrehan Lake Boulevard and Murphy Lake Boulevard. It is a huge gravel lot and you will not have any trouble finding a spot.
There were public restrooms next to the trail entrance as well as a water fountain.
All kinds of surfaces. Dirt and gravel trails, two-track roads, gravel roads, paved roads. Watch out for exposed roots and rocks on some of the dirt trails. Some of the trails contained occasional patches of mud which could be jumped over or easily circumvented. There were also a few wooden bridges over the larger streams. One trail led directly into a lake but we found a sturdy beaver dam nearby which we used to get across.
The first part of the route is VERY hilly with a seemingly endless array of steep 20 to 70 foot hills. You might be inclined (pun intended) at first to run up the hills but you will soon discover that walking is the better choice. The rest of the park was mildly hilly.
There is an annual race here called Surf The Murf. The route is a 17.5 mile loop and you can choose to do 1, 2 or 3 loops which equate to a 17.5 mile (obviously), a 50k and a 50 mile race. The route in this map is primarily that route with a few shortcuts taken.

Once you make it through the hills in the northern portion of the park, it levels off. There are a few sections closed off with gates but you can tell by the worn paths around them that they are largely ignored. There was one trail that was definitely off-limits and it was clear from the barriers that absolutely nobody was allowed.

There is a portion where you will likely need to leave the park and run on highway which eventually turns into a gravel road. It is only about a mile before you re-enter the park on the right side.

You will see a lot of small lakes brimming with wildlife. At one point in fact, the trail actually led right into the water. Your options are to wade through the water, backtrack and take a different route or walk across the top of a beaver dam. The best option is the beaver dam. It is about 40 feet across, surprisingly sturdy and easy to walk across.

You will be able to tell when you are getting close to where you started by the topography. It quickly changes from fast, open fields back to the familiar hilly, wooded terrain. This does not last long however and, before you know it, the parking lot where you started from will appear out of nowhere.