The trails at the front of the park are very easy, level, graded and sometimes paved (for wheelchairs), but further back in the park along the Vista Loop there are some pretty steep, rocky sections with a little bit of huffing and puffing.  Nothing particularly impressive, just a normal walk through the woods.  Constant highway noise (it's right off a major freeway), that does die off to just a faint background hum in the back half of the park.  Trails are extremely well marked and maintained (almost to the point of overkill).