What: Rachel Carson Challenge, a one-day, noncompetitive 35-mile hike When: June 19, sunrise to sunset Where: Harrison Hills Park in Harrison to North Park in Pittsburgh's North Hills Details: Conservancy's website, rachelcarson trails.org. TribLIVE's Daily and Weekly email newsletters deliver the news you want and information you need, right to your inbox. While the pandemic caused a flurry of event cancellations last year, some outdoor outings are a “go” this summer, including the 24th Rachel Carson Trail Challenge. The 35-mile trek though rugged, hilly terrain only adds to the challenge of the event, which will start in Harrison Hills Park in Harrison at sunrise and finish at North Park in Pittsburgh’s North Hills by sunset.