Urban Nature Stringer's Ridge 10k: Saturday, 9 a.m., from Coolidge Park; 5k on road, 5k on trails; part of RiverRocks; $35. Sign up at www.ultrasignup.com/register.aspx?did=14344.
Triple Crown bouldering competition: Saturday, Stone Fort. See www.triplecrownbouldering.org.
Chattanooga Head Race: Saturday, rowing competition in Tennessee River. See www.chattanoogaheadrace.com.
Swim the Suck: Saturday, Tennessee River. See www.swimthesuck10mile.com.
Chattanooga Trekkers hike: Saturday, 1 p.m.; longer and shorter options on Laurel-Snow section of Cumberland Trail. Contact Valerie Radu at valerie.radu@gmail.com or 503-2318.
Cloudland Canyon guided cave tours: Saturdays and Sundays in October; 2- to 4-hour tours led by Georgia Girl Guides; ages 6-older (minors must be accompanied by adults); reservations required. See www.gastateparks.org/CloudlandCanyon.
Downriver kayak trip/bike ride: Sunday, 1 p.m., paddle from Chickamauga Dam to Coolidge Park, then pedal back via Tennessee Riverpark; $45, includes all gear. See www.outdoorchattanooga.com/2716.htm.
Rapid Learning Whitewater Club roll practice: Tuesdays, 6:30-8:30 p.m., UTC indoor pool; ages 8-older; $5, equipment provided. Email terri@outdoorchattanooga.com or call 842-6629.
Local Tenn. Ornithological Society meeting: Oct. 13, 7 p.m., Ascension Lutheran Church, 720 S. Germantown Road. Contact David Stone at rockyturf@comcast.net or 238-4234.
NERA's Paddle to End Alzheimer's: Oct. 15, Oostanaula River, Gordon County, Ga.; 10-mile family option or 23-mile "extreme" version; New Echota Rivers Alliance. Contact Dan McBee at mcbee.dan3@gmail.com or 706-263-4002 or Karen Parrott at kparrott@ngnb.net.
Chickamauga Battlefield free bicycle tour: Oct. 15, last one of year, 9:30 a.m., visitors center; adults & kids 8-older accompanied by adults; guided at leisurely pace. Call 706-866-9241 if rental bicycle needed.
Kayak for Conservation: Oct. 15; fully supported trip through Tennessee River Gorge, lunch at Pot Point Cabin, after-paddle event at Rock/Creek; $100, benefiting Tennessee River Gorge Trust preservation & education work. Email sarahq@trgt.org or call 266-0314.
Tennessee Wild hikes: Oct. 16, 2 options, each for 12 participants; easy 6-miler on Benton MacKaye Trail through Little Frog Wilderness (contact Dick Evans at richardevans@wildblue.net or 828-479-2503); strenuous 11.8-miler with nearly 2,500-foot elevation gain along Licklog Ridge Trail in Big Frog Wilderness (register at www.tnwild.org/get_involved/outings/registration or contact Jeff Hunter at jeff@safc.org or 322-8766).
Women's Hang Gliding Festival: Oct. 27-30, Lookout Mountain Flight Park; for pilots and women who want to try hang gliding; fun flying competitions, clinics, reduced-price training, evening activities. See www.hanglide.com or or email fly@hanglide.com or call 706-398-3541 or 800-688-5637.