Biking, paddling and running solo for a total of almost 40 miles sounds hard enough, but imagine carrying your bike on your back as you hike several miles up Mount Ripinksy so that you can ride down in a training session.

“That’s pretty good exercise,” said Garrett Montgomery, of Haines, who will compete solo in Sunday’s second-annual Chilkat Challenge Triathlon. “I’m really looking forward to the running section, though. That’s my best vehicle.”

As to his other “vehicles,” Montgomery added, “I bought a fancy mountain bike and a kayak just for this race.”

The triathlon starts at 10 a.m. Sunday, when about 80 racers are expected to put in at Mosquito Lake and paddle 7.5 miles downriver to Klukwan — kayaks, rafts, standing paddleboards — where they will take their seats on bicycles and ride 22 miles to Fort Seward in Haines, then run 9.5 miles to Chilkat State Park.

Advance sign-ups for the race — more than 80 solos and team members — are about double the amount of last year. Racers are required to attend a pre-race meeting at 6 p.m. Saturday at the Chilkat Center lobby.

“I’ve never done a triathlon before, so my goal for myself is just to finish and to feel good while doing it — and afterward,” Meredith Trainor wrote in an email. She is coming up with a group of 15 from Juneau. Though most of them will be competing as relay teams (notably the Southeast Alaska Conservation Council team, back again after taking second place in their division last year), Trainor will be racing solo.

“I’ve been running, kayaking and biking all month to make sure I’m in shape for it,” Trainor said. “My partner and I are actually heading out to kayak on the lower Lynn Canal tonight to practice.”

Rustin Gooden, of Haines, who finished fourth last year in the men’s solo division, relishes the competition. “I’ve been focusing on cross-training for the transitions: switching from kayak to bike, biking to running.” He said he’s been running on the notoriously steep Mount Riley Road.

“The other big challenge will be the final run downhill to Chilkat State Park. After 30-some miles, your legs are going to be tired and that hill is going to be killer on the knees. I think a lot of people will walk.” The park road has a 14 percent grade in places.

One obstacle for the race this year is highway construction 10 miles north of Haines. Racers will have to navigate about four miles of gravel during the biking leg. The Chilkat Challenge’s website advises that racers might want to consider non-road bike tires. The Kluane-Chilkat International Bike Relay, which recently traced the same part of the road, advised its participants to use wide road tires or switch to a mountain bike for that section.

“The construction crew put down hard-packed crushed gravel. It wasn’t too bad to ride on; skinny road tires cut into it, though,” said Gooden, who was in the bike relay. “I’m going to put 38-millimeter hybrid tires on my road bike.”

Rocks and training and tired legs aside, “This race really showcases the beauty of the river and why we all come to live here,” Gooden said. “The upper Chilkat and the Council Ground, Klukwan and the heart of the Alaska Chilkat Bald Eagle Preserve. It’s such an incredible place, and people don’t often go there on their own. Events like this really give you the excuse, and a safe way, to get out there.”

Trainor struck a similar tone. “This is an awesome event with a great and beautiful course — who wouldn’t want to take the ferry up with a group of friends to participate on a beautiful summer weekend?”