After more than three decades of planning for growth in Utah County, Darrell Cook is retiring.

The director of the Mountainland Association of Governments is stepping down at the end of the year and taking 38 years of experience with him.

The highs

Cook said his highest moment is right now.

In 2000, he got together with the government leaders who make up MAG -- which covers Utah, Wasatch and Summit counties -- to talk transportation. On the schedule? Interstate 15 expansion.

"It's a pretty monumental task," he said.

It takes about 15 years from start to finish on a project that big, and while I-15 construction through Utah County isn't done, it has begun and there are a dozen other major road projects slated for completion in the next four years.

The lows

In 2005, disenchanted with how MAG was handling aging services and administrative costs, among other things, Utah County commissioners voted to leave the organization.

"That was pretty traumatic," Cook said. "We spent, I'd say, the better part of a year and a half defending the things we did."

More than two years later, county commissioners voted unanimously to rejoin MAG after funding concerns were addressed.

Unforseen

Planners are expected to foresee what's coming down the pike, but Cook said no one saw just how fast the region's population would grow. The three counties had a combined 150,000 residents in 1970. This year it's well over 600,000 and there are more than a dozen new cities that have sprung up.

Those cities -- like Eagle Mountain and Saratoga Springs -- are pushing the population west.

"You see us playing a lot of catch-up," he said, especially with east-west roads.

Salt Lake County's No. 1 transportation concern is east-west congestion and it has 50 total major lanes that run in that direction. At half the population, Utah County has just four lanes.

The west side, Cook said, is emptying of jackrabbits and filling up with subdivisions that could easily double the valley's population over time.

The bridge

Perhaps the most controversial transportation proposal in the valley is whether or not to find a way across Utah Lake. There is currently a private proposal on the table for a bridge that would run from 800 North in Orem to Pelican Point.

Whether or not that proposal will be the one to succeed, Cook doesn't know. But, he said, it will happen.

"It has to happen," he said. "It's not a matter of if, it's a matter of when."

Advice

Over the next three months, Cook will help find a new director and try not to think too hard about the warm weather in California where he expects to spend a substantial amount of his time.

He said his biggest mistakes have been in not getting unanimous consent from the screening committee when making a new hire. If there's a split decision, keep looking, he said.

His best advice is this:

"Listen to others, consider the alternatives, and follow your instincts."