In some circles, "mommy track" means leaving a career to raise children. In Lafayette, it means circling the verdant, three-mile paved path around the town's reservoir. Lafayette Reservoir entices not only legions of active mothers exercising with their babies, but anyone who enjoys a scenic walk through classic California terrain. Bonus features of the 925-acre site include hiking trails in the hills above the reservoir, a soon-to-be-updated play structure, and plenty of open grassy areas for Frisbee or soccer. Dogs on leashes are welcome. If you're not inclined to walk, bring a fishing pole. If you don't want to fish, bring one to eat: The 135 picnic tables and barbecues scattered throughout the park await. The reservoir is off Highway 24, about a mile from the Lafayette BART station, on Mount Diablo Boulevard.