Located just 8 miles NE of downtown San Diego, Mission Trails Regional Park spans almost 5,800 acres and boasts over 40 miles of trails, making it one of the largest urban parks in the United States.
While there are a number of trails limited to foot traffic only, a majority allow bicycle (and some horse) access. Terrain varies from mellow doubletrack to the NE of the park, to nice easy singletrack (SW), to the extreme at the North side of North Fortuna Mtn. Climbs in the middle of the park are steep - 450-500' in ~half a mile - and can be loose.
Major Trail Summary:
Father Junipero Serra Trail:Paved road shared (1 lane traffic SW to NE only, 1 lane foot and bikes both ways) by vehicles and visitor traffic. Connects the visitors center area with Mission Dam (foot only, but beautiful) and Grasslands Loop trails as well as the campground.
Grassland Loop: Accessed from the Mast Blvd parking area in Santee, or from Grasslands Crossing from Father Junipero Serra Trail. Very mellow doubletrack - good for family outings with youngsters.
Oak Grove Loop: Trailheads are at the SW end of Fr Junipero Serra Trail, on the east side. Nice pleasant singletrack - good loop to add to a warmup ride, or for families with kids.
Visitors Center Loop: Mostly singletrack with some waterboards and 1 significant hill. Widens to the northwest and provides access to the San Diego River Crossing trail. This ford is closed when the water is up.
Mariposa Gulch:Connects the Grasslands loop with Fortuna Saddle and North perimeter trails. Hilly doubletrack but not all that steep.
North Perimeter Trail:Steep, loose doubletrack with large jagged rocks. Think bulldozer trail blasting straight no matter the terrain. Connects to the North end of North Fortuna and Shepherd Pond Loop from Mariposa Gulch.
Fortuna Saddle Trail: Steep at times doubletrack ranging from Mariposa Gulch to the East, all the way to the River Crossing to the West. This trail could be considered the "spine" of the system, crossing the Fortuna Mtns, with many intersections to side trails on the West side of the saddle. Some very nice singletrack can be had on the west side of the summit, to the north of the trail, connecting over to Shepherd Pond Loop. Look for these intersections between the Summit and Suycott Valley trail.
South Fortuna:Out and back from the top of Fortuna Saddle. Fairly easy doubletrack with some loose rocky sections. Note that the trail south of the summit becomes foot only.
North Fortuna:Connects Fortuna Saddle with North Perimeter and Shepherd Pond Loop via the top of North Fortuna Mtn. Steep doubletrack to the south of the summit, even steeper and technical singletrack to the north.
Suycott Wash:Nice pleasant singletrack connecting the west end of Fortuna Saddle with the SD River Crossing.
Suycott Valley:Mellow doubletrack connecting Fortuna Saddle with Shepherd Pond Loop and Rim Trail.
Shepherd Pond Loop:Mostly doubletrack with some steep sections. Trailhead (currently closed for construction) on Portobelo Drive in TierraSanta. Connects with North Fortuna, Rim Trail, and Suycott Valley. Some nice singletrack side trails exist in this area.
Rim Trail:Connects SD River Crossing with Suycott Valley via twin towers and to the West end of Fortuna Saddle. Begins (to the south) as gravel road, becomes doubletrack as you progress north.
*Quarry Loop Trail:Trailheads at Clairemont Mesa Blvd and Calle de Vida in TierraSanta. Connects with SD Crossing, Rim and Fortuna Saddle.*Currently inaccessible due to construction
San Diego River Crossing Trail:Gravel Road. Connects Visitors Center Loop with all trails to the west of the park. Ford over the river is closed when the water is up, and also closed at times due to construction.
If you'd prefer a loop of the entire park rather than an out and back or lollipop, I'd recommend a counter-clockwise loop. Start at the visitors center if you want a warm up, proceed NE on Father Junipero Serra trail (paved) with optional hits on Oak Grove and Visitors center loops. Cross the river at Grasslands Crossing. Without the warmup, begin at Mast Blvd at Grasslands loop. Proceed NW on Grasslands loop to Mariposa Gulch. Take either Fortuna saddle or the perimeter trail west to cross over Fortunas. From there, take your pick of routes West and South over to the final downhill at the SD river crossing trail. Note that the crossing is closed at times due to water levels and sometimes due to construction. Check at the visitors center if you can't afford an unplanned return the painful (steep) way. To make the route more difficult, simply reverse the direction - the climbs are more abrupt when taken in a clockwise fashion.