IF YOU’D RATHER practice your backstroke to the call of a red-breasted robin than the din of splashing kiddies shouting “Marco! Polo!” at the public pool, you’re living in the right town. There are dozens of man-made and freshwater swimming holes in the Portland area, and the month of August, when Oregon’s thermostat can soar into the triple digits, is the best time of year to check them out. So take an afternoon off—heck, an entire day—and show your brood how to make a splash the way Mother Nature intended.

1. PEGLEG FALLS

Don’t be surprised if you’re all alone at this lightly visited hole near ?Mount Hood’s Bagby Hot Springs. The best area for swimming is to the right of the rushing 15-foot falls, though you should avoid swimming at their base, as the current is strong. The pool is 60 feet wide, and there’s plenty of space to relax on the flat rocks that border this unspoiled mountain escape.

FROM ESTACADA Take Hwy 224 east and turn right on FR 46. Then turn right on FR 63 and right again on FR 70. The falls are on the left.

2. BLUE LAKE

This 64-acre natural lake in the Northeast ’burb of Fairview is a classic spot for web-footed families. Fed by underground springs, its marked-off shallow swim zone and calm waters make it great for kids (note, though, that they must be at least 5 years old to swim). If you prefer to stay dry, catch some rays on the 150-foot-long beach and take in the stunning view of Mount Hood.

FROM PORTLAND Take I-84 east to Exit 14. Go left on NE Fairview Pkwy, right on NE Sandy Blvd, and left on NE 223rd Ave. Follow the signs ?to Blue Lake Regional Park.

3. BUCK LAKE

After hiking the half-mile in, swimmers often are inspired to go au naturel upon arriving at this five-acre alpine lake located at 5,600 feet (hence its nickname, “Buck Naked”). The 72-degree water is crystal clear 30 feet down to its sandy bottom. But don’t forget to take in the sights—two rock falls, bright red maples, possibly a nude hiker—that make the lake a summer staple.

FROM ESTACADA Take Hwy 224 east. Turn left on FR 57 and left on FR 58. Turn right on FR 5810, which turns into FR 210. The lake is on the left.

4. BLACKWELL PARK

Willamina Creek bends around a shady grove of white oaks before cascading over sculpted bedrock formations. (It’s the kind of country nook Huck Finn might have stopped at to cool his heels.) If it’s not too cold, immerse yourself in the lazy water; the mellow current and eight-foot depth make it the perfect ?place to float about after enjoying a leisurely picnic lunch.

FROM MCMINNVILLE Take Hwy 18 west to Hwy 18B through the town of Sheridan. Turn right at Willamina Creek Rd and follow the signs to Blackwell Park.