Lined Up 
Thrill-seekers are taking to the skies this summer—and we don’t mean in airplanes. Here, five Colorado zip line adventures for an aerial adrenaline rush.
Close To Home
Denver Zipline tours
The Draw: Colorado’s fastest zip line—and the closest course to Denver (guides will transport you to and from downtown or the Tech Center for $10/person)—is best enjoyed by booking a combo package ($175), which tacks on a guided rafting, hiking, or rock climbing excursion.
By The Numbers: Six lines, 850 to 1,906 feet long, are rigged 230 feet above a pine-covered valley.
Thrill Factor: Hit up to 55 mph on the steep finale, dubbed the Screamer.
Book It: $119, denverziplinetours.com 
The Draw: Family-friendly adventure (it caters to kids as young as two) blends with sweeping Vail Valley views. Your 10-minute ride from the Wolcott meeting spot to the course is in an Austrian military transport vehicle.
By The Numbers: Six lines, 200 to 1,000 feet long, dangle you 200 feet above Alkali Creek Canyon.
Thrill Factor: Starting in July, leap from the rim of the canyon on the 100-foot rope swing.
Book It: $150, zipadventures.com 
Young At Heart
The Draw: The state’s first zip line, which opened in 2005, is adding Colorado’s only European-style aerial park—a grown-up playground made from swinging bridges, tightropes, ladders, and obstacles—this month.
By The Numbers: Seven lines, 80 to 700 feet long, run 100 to 200 feet above Lost Canyon.
Thrill Factor: Race a friend on the two parallel Adrena-Line cables.
Book It: $89 (zip line), $59 (park), captainzipline.com 
Soaring Tree Top Adventures
The Draw: One of the world’s longest courses—accessible only by a private car on the Durango & Silverton Narrow Gauge Railroad (included in the fee)—whisks you through old-growth aspen and pine for an all-day excursion and a four-course lunch.
By The Numbers: Twenty-seven lines, 56 to 1,400 feet long, combine for almost two miles of zipping.
Thrill Factor: Zip upside down over the Animas River.
Book It: $459, soaringcolorado.com 
Crested Butte ZipLine tour
Crested Butte Mountain Resort
The Draw: This on-mountain course is a bonus to skiing, snowboarding, or mountain biking. A 20-minute hike takes you to the 9,300-foot starting area. Ride rain, snow, or shine.
By The Numbers: Five lines, 120 to 400 feet long, are connected by three suspension bridges and eight lofted platforms.
Thrill Factor: Up the ante by riding backward with your eyes closed.
Book It: $60, skicb.com/zip 
Note: Fees are for one run of the complete course. Most adventures average 2.5 hours.