Dwight Johnston, chief economist for the California and Nevada Credit Union Leagues, said several credit unions in the two states launched into 2018 like they did this time last year: hitting new records in membership, loans and deposits—or at least making major inroads to where they stood 10 years ago as the "Great Recession" began.

"The trends will last as long as the economy continues to perform well," Johnston said. "The big regional areas of southern California and the Bay Area will perform the best, and larger credit unions will outperform smaller credit unions."

Loan growth will continue but at a slower pace "only because the base number is bigger," he said.

In Nevada, where assets grew 8% to $4.8 billion in the 12 months ending Sept. 30, credit unions should enjoy another year of good growth. "The state still has an ample pool of available workers, and reasonable home prices make it attractive for relocation."

Johnston said the economy might start running out of steam by late 2018. His concerns include:

• A tight labor market. Employers are having increasing difficulty finding workers, which will be a limiting factor for the economy.
• A sellers' housing market. The supply of homes in most markets are reaching historic lows and could tighten further as homeowners stay put due to the upcoming decrease in property tax deduction stemming from the new tax law.
• Rising interest rates. This will further shrink the mortgage refinance market.

One hallmark of Region 5 is that the average asset size of its credit unions is twice that of the rest of the country. Half of the top 10 credit unions by assets are based in Region 5:

• BECU, Seattle ($17.6 billion, 1.1 million members)
• SchoolsFirst, Santa Ana, Calif. ($13.9 billion, 779,810 members)
• The Golden 1, Sacramento, Calif. ($11.3 billion, 902,074 members)
• First Technology FCU, Mountain View, Calif. ($11.1 billion, 500,874 members)
• Star One CU, Sunnyvale, Calif. ($9.5 billion, 101,004 members)

State and regional rankings are skewed by the disproportionate size of bigger credit unions, especially Navy Federal Credit Union based in Vienna, Va. ($83.7 billion in assets, 7.4 million members), which accounted for more than half of Virginia's total assets and three-quarters of its net income as of Sept. 30.

For example, Virginia's 3.8% return on average assets (ROA) for the first nine months of 2017 leads among states because it includes Navy Federal's 4.8% ROA. Excluding Navy, the state's ROA would fall to 2.3%, which is slightly below the U.S. average.

Navy even can sink Region 2, comprised mostly of Mid-Atlantic states. Navy's $978.5 million in net income accounted for more than half of the region's $1.8 billion total for the first nine months of 2017. The region's ROA is 2.8%, up 13 basis points from a year ago—the best regional ROA in the nation, behind the southern Region 2's ROA of 2.3%.

Without Navy, Region 2's ROA would drop to 1.9% with essentially no change from a year earlier. Then it would more closely resemble the rest of the Northeast in Region 1, where ROA was also 1.9% with little change.