The Mt. McCoy Trail is located on the west side of Simi Valley with a trailhead at the corner of Washburn Street and Los Amigos Avenue (off the west end of Royal Avenue).
The Mt. McCoy trail is distinctive as there is a large white cross at the top of the mountain, which is about a 600 or so foot climb. From the trailhead, go straight and then take the switchbacks up the mountain.
Actually, after just a few hundred feet from the Washburn/Los Amigos trailhead, you'll reach a juncture where you either go straight (which is correct) or take a trail to the right, which is much steeper, but a much more direct path to the top. We made the mistake of taking that path the first time and it got us right up to the cross, but it is pretty steep.
The trails here are all really nicely groomed, thanks to the Rancho Simi Trailblazers and RSRPD. There are dozens of "shortcuts" along the trail but try to stick to the main path. Taking the correct path, with its switchbacks and twists and turns, is a bit over a mile to the top of Mt. McCoy, where you will be treated to panoramic views of the entire Simi Valley and the other direction towards the Reagan Library. In fact, there are paths from the top that take you in other directions, including a fire road that intersects with Presidential Drive to the Reagan Library.