OC Marathon course map and elevation.

How I’d run it, stretch by stretch

Miles 1 and 2: Fashion Island and down MacArthur

Over these 2 miles the course climbs 84 feet and drops 137, 53 feet net down. The climb: Around Fashion Island from mile 0.0 (+44 feet over 0.6 mi, 1.5%).

The gun goes at 5:30, in the dark, and the first mile climbs about 80 feet around Fashion Island to the highest point of the course. Then MacArthur Boulevard drops about 130 feet toward the ocean. Don’t let the downhill pull you under goal pace this early. The half starts an hour behind you, so the road is yours.

Miles 3 to 5: Corona del Mar, Ocean Boulevard and down to the harbor

Over these 2.8 miles the course climbs 67 feet and drops 136, 68 feet net down.

PCH through Corona del Mar, then Ocean Boulevard along the bluff above the beach, with the ocean on your left as the sky gets light. Carnation Avenue rises about 30 feet, and then Marguerite and Bayside drop about 95 feet to the harbor. Find your goal pace here and settle into it.

Miles 6 and 7: Bayside Drive and the PCH bridge

Over these 2.2 miles the course climbs 22 feet and drops 56, 34 feet net down.

Two flat miles along Newport Harbor on Bayside Drive, then PCH and the bridge over the mouth of Upper Newport Bay. This is the easiest running of the day. Bank calm, not seconds.

Miles 8 to 10: Dover Drive and the Back Bay bluffs

Over these 3.6 miles the course climbs 127 feet and drops 74, 52 feet net up. The climb: Dover Drive to Castaways Park from mile 7.1 (+67 feet over 0.9 mi, 1.4%).

The race’s first real hill: Dover Drive climbs about 65 feet to Castaways Park, and then bluff paths and Galaxy Drive run above the Upper Newport Bay reserve, where the neighbors come out. Take Dover by effort and let the pace go. The bluff miles roll gently, with a few tight turns on the park paths.

Miles 11 to 14: Irvine Avenue, Red Hill and the 405

Over these 4.1 miles the course climbs 117 feet and drops 149, 30 feet net down. The two climbs: Irvine Avenue from mile 11.1 (+41 feet over 0.3 mi, 2.6%); The 405 overpass from mile 14.2 (+41 feet over 0.2 mi, 3.3%).

Down Santiago Drive and back up Irvine Avenue, about 40 feet, the second hill. The half marathon peels off at Mesa Drive just past mile 12, and the marathon gets lonely fast. Red Hill Avenue runs past John Wayne Airport to the 405 overpass at mile 14.4, another 40 feet you can see coming for half a mile. It’s the last climb of the day.

Miles 15 to 18: Irvine, the Segerstrom Center and South Coast Plaza

Over these 3.8 miles the course climbs 30 feet and drops 30, about level overall.

Flat from here on, but full of turns: a loop through a corner of Irvine, Sunflower Avenue to the Segerstrom Center, over Bristol Street on the footbridge to South Coast Plaza, and through the Segerstrom High School campus. Every turn costs a little. Run the tangents, keep your rhythm through the corners and stay on top of your fueling.

Miles 19 to 21: Segerstrom Avenue and the Santa Ana River Trail

Over these 3.3 miles the course climbs 32 feet and drops 49, 16 feet net down.

West on Segerstrom Avenue to the Santa Ana River and about a mile and a half on the river trail’s east levee. It’s exposed and quiet, and when the sun is out it gets warm here. Drink at every station, and break it into pieces: the levee, then the footbridge, then the neighborhoods.

Miles 22 to the finish: Mesa Verde, the Bird Streets and the OC Fair

Over these 4.4 miles the course climbs 76 feet and drops 33, 42 feet net up.

Over the Gisler footbridge into Mesa Verde, a gentle rise of about 40 feet up Country Club Drive, then the Bird Streets, where the neighborhood comes out, and Merrimac Way past Orange Coast College into the fairgrounds. It’s flat and loud at the end. Whatever you have left, use it here.