When valley temperatures peck away at the 90-degree mark, it’s not unusual to see a line of boats snaking down the ramps at Highline Lake State Park.

That’s particularly true on busy summer weekends when the 40-boat maximum often is reached by midmorning.

This year, there’s something new for boaters to do while awaiting their spot on the lake: They can look for mussels.

A rigorous inspection system aimed at slowing the spread of aquatic nuisance species is in effect at all water recreation-based state parks including Highline Lake and Crawford, Rifle Gap and Harvey Gap reservoirs.

This has nothing to do with those pesky twin nephews of yours, but instead focuses on other nuisances, particularly zebra and quagga mussels, two miniscule mollusks threatening to cost boaters and water managers millions of dollars in preventive steps.

State regulations in force this year require all boats going out of state (think Lake Powell or Flaming Gorge Reservoir) and then returning to Colorado to pass a state-certified inspection prior to launch. Also, any boat launched on a Colorado mussel-positive lake also must pass an inspection prior to launching at a new location.

Joe Steggs of Fruita shows where the bilge plug is missing from his boat, a move that allows water to drain from the bilge and prevent zebra mussels from being transported. Photo by Dave Buchanan

This summer, boaters are feeling the pinch because launching a boat is prohibited without a certificate or seal and because inspection stations aren’t open 24 hours. Boaters must plan ahead to catch inspection stations during open hours.

Inspections are done prior to launch and, in some cases, after leaving the water. If your boat’s bilge and motor are drained of water, the inspections may take 10 minutes or less, but unprepared boaters can plan 30 minutes or more for a more-detailed inspection that may include a hot-water bath to flush out and kill suspected exotic hitchhikers.

“If it’s busy we’ll send them to park headquarters” for the hot-water wash, said Linda Herrera, a Highline Park ranger, who was cooling her heels on a recent sultry Monday morning while waiting for more boats. “But we do most boats right here in just a few minutes.

“We must have done 100 inspections (Sunday); we were swamped,” she said.

Joe Steggs of Fruita was pulling out after a morning of boating on Highline Lake and stopped long enough to let Herrera snap a special cable seal onto his boat that will allow him to launch when the inspection station is closed.

Herrera looped the steel cable around Steggs’ boat winch and an eye bolt on his boat.

“This way, if he comes back here or goes somewhere else, he can show them his inspection certificate and the seal, and they’ll know he hasn’t been in the water since his last inspection,” Herrera said.

Steggs also takes care to do what all boaters are requested: Clean, drain and dry his boat.

“I’m a regular here so I’m pretty familiar with the procedure,” said Steggs with a laugh. “I pull the plug from the bilge and let all the water out before I leave the ramp. So far, I haven’t forgot to put it back in before I launch my boat.”

Steggs and his son, Josh, are aware of the damage mussels can inflect on the workings of a pricey boat motor and are supporters of the anti-invaders program.

“We already have $8,000 tied up in the new motor, and we don’t want to lose it,” said Josh, showing off the shiny black prop recently installed on the motor.

The elder Steggs nodded in agreement.

“I’ve heard how the mussels can get into the motors and ruin them and I don’t want that to happen to me or anyone,” he said.

“I won’t go to Flaming Gorge (Reservoir) because it’s so infected, and I’m not going to leave my boat in the water at Lake Powell or Blue Mesa.”

Both of the latter are suspected to harbor zebra mussels.

Still, the less you leave your boat in the water, and the better you drain the motor and bilge, the less likelihood there is of harboring or transporting zebra mussels, said Allen Martinez, Highline Park manager.

“Since we don’t have any on-water boat storage, we don’t have the problems other reservoirs have,” he said. “But if we ever get zebra mussels, boaters here will face more hassles and tighter inspections when they go someplace else.”

Zebra and quagga mussels, which spread from Europe to the Great Lakes in 1988, made their Colorado appearance in Lake Pueblo in January 2008.

“Most of our boaters support the inspection program,” Martinez said. “But about a quarter of our boaters couldn’t care less and aren’t taking the simple precautions of making sure their boats are cleaned, drained and dry.”

Email DAVE BUCHANAN