Roughly one year into the U.S. trade war with China, importers and exporters are still finding workarounds for the tariffs. But with new tariffs going into effect this month and no end to the battle in sight, experts say it may be only a matter of time before the full impact is felt.

The ripple effect will reverberate throughout state economies in a myriad of ways. But it's California that stands to lose the most, trade experts say. In terms of sheer volume, California conducts more trade with China than any other state in the country. Total trade with China tops $175 billion. That, along with the flow of Chinese investment into the state, can seriously impact California's GDP growth and crush its $2.7 trillion economy.

The latest escalation in the trade war, with some tariffs rising to 25% on June 1, comes as overall economic growth in California begins to cool. The state's economy grew by 3.5% in 2018. That pace slowed to 2.% in the first quarter of 2019, according to the U.S. Commerce Department.

For now, shippers are girding for the fallout.

At the Port of Oakland in California, Maritime Director John Driscoll said he was surprised last week when volume of containerized agricultural exports for May came in 8.4% higher than one year ago — the third consecutive monthly increase.

"What we feel from talking to customers and talking to users of the port is that they are finding other markets. They're tapping other things. They're being creative of where they're sending their products to other countries," Driscoll told CNBC.

Agricultural exports rose 12% in the first four months of the year, led by increases in shipments to Taiwan, Vietnam, Korea and Japan. Ag exports to China also rose despite the tariffs, but only by 5%.

Driscoll believes that in addition to finding alternative markets in Asia, some exporters are still "front-loading" — trying to get shipments in ahead of even steeper tariffs to come.

"It very well could be that this is still a residual impact of importers and exporters trying to get in and out before they don't know what's going to happen next in the future," he said.

All of which suggests that the increases in volume could be only temporary.

"We're a little bit skeptical to know what's going to happen in the future, because we've seen a lot of front-loading," Driscoll said. "So the unknown and the uncertainty is if this continues and tariffs impact these volumes in the future, we could see some falling off of our volumes."