San Diego has 725 miles of mapped trails, 2.2 for every square mile of land

The longest trail networks: Los Peñasquitos Canyon Preserve, 53.9 miles; Mission Trails Regional Park, 51.2 miles; Balboa Park, 28.2 miles; Black Mountain Open Space Park, 23.7 miles. Each one is on the map above, with directions to the nearest trailhead or parking.

26% of its land, against a typical 4% for a California town and 4% nationally (PAD-US). Conserved doesn’t always mean open to visitors: easements are usually private land.

OpenStreetMap records dogs as welcome at Los Peñasquitos Canyon Preserve (on leash), Balboa Park (on leash), Black Mountain Open Space Park (on leash) and Tecolote Canyon Natural Park (on leash). For the rest, check the signs at the trailhead.

856 miles of bike routes are on the map: 633 of painted or protected lanes, 118 of off-road paths and 105 of shoulders and shared lanes. Named routes: Tecolote Canyon Trail, Hillside Loop and Carmel Mission Bike Trail.

148,576 acres of parks and open public land lie inside San Diego or within 10 miles of it (PAD-US), 39,058 of them inside the city line.

Ahead of 97% of U.S. towns on the Outdoors grade, #74 of 847 in California. The grade combines the share of land that is conserved, miles of mapped trail per square mile of land, park acres per 1,000 residents and the share of residents within a half mile of a park. It’s a character grade, so it isn’t part of the overall grade. How it works.