C limber Megan Mascarenas is very much a "tweenager," stuck between the two different worlds of childhood and adulthood.

The 15-year-old climbed at her first "adult" bouldering nationals this year, taking fourth at ABS open nationals in a field of accomplished veterans like Angie Payne and Alex Johnson. The very next weekend, she competed at ABS youth nationals and took second in her division.

She got her learner's permit last October, but her mom Staci Mascarenas said she isn't sold on letting Megan drive from their home in Colorado Springs to Boulder two to three times a week. They've been making the roughly two-hour drive -- often through I-25 traffic -- since Megan joined Team ABC in Boulder in 2010.

"Sometimes she's just a kid," Staci Mascarenas said. "This morning she was eating her cereal and watching cartoons. But her maturity is a lot more than most 15 year olds. She takes everything very seriously. (She's in) that in-between adult/child phase."

While Megan is working at the ABC Climbing Gym, 1960 32nd St., Boulder, her mom said she heads over to The Spot, 3240 Prairie Ave., Boulder, to climb, too. Staci and Megan started climbing at the same time; Megan was 3 or 4, and Staci was in her early 40s.

Because she'll turn 16 this calendar year, Megan said she was allowed to compete at open nationals for the first time. Though she didn't have any expectation going into finals, Megan said she did her usual pre-competition routine --"hibernate," or use as little energy as possible, and get focused.

Now that she's seen the "adult" nationals world, Megan said she preferred competing against veterans and pros, to climbing with kids. Boulder climber Alex Johnson, who finished sixth at nationals, said she and other more-experienced climbers adopted Megan and gave her a few pointers about staying relaxed during finals.

"It was more fun because adults are more chill and they know more about climbing than kids," Megan said. "It was cool to talk to them and learn from them."

And the adults noticed her, too.

Veteran climber Angie Payne competed in bouldering finals with Megan. Payne finished fifth, just behind Megan, and said she couldn't believe how young Megan was. It brought back memories for Payne of living in two climbing worlds: one filled with adults, and one filled with kids.

"There's a whole new generation and now they're entering the adult competitions," Payne said. "That's amazing. She's 15, and she's in finals. You see her going through it and remember. I'm nostalgic."

Even though it means driving to Boulder from Colorado Springs several times a week, Staci said she's happy that Megan feels like she's part of the climbing community. Staci works part time as an X-ray technician and Megan gets out of class at Thomas B. Doherty high school, where she's a freshman, one period early so they can get to Boulder by around 4:30 each afternoon.

Megan also trains with a private coach, Kevin Branford, in Colorado Springs, but said most of her school friends don't understand her sport. The Team ABC kids get it, and Megan said she hopes to attend the University of Colorado-Boulder for college so she can live and climb in Boulder full time.

She knows she won't be able to climb forever, so Megan said she plans to become an emergency room doctor. She likes the idea of helping people while feeling the rush of adrenaline in the ER, she said, and the stories her older brother, an emergency room RN, brings home are "really exciting."

For now, she said she'll keep doing her homework in the car on the long drives north to Boulder, playing with her Rubik's cube before competitions, training her dog Storm to do tricks and pushing both the kids and the adults in her life to be better.

"She inspires me," Staci said. "If I'm working on something, she's encouraging me, 'Don't come off that wall, Mom.'"

--Follow Sarah Kuta on Twitter: @SarahKuta.