The driver was stopped on the shoulder of Highway 518 in Burien, south of Seattle, on Tuesday evening.
The agency tweeted a photo showing a blue foam square, with the phones sitting in eight rectangular cutouts.
Trooper Rick Johnson is a spokesman for the patrol and said Sgt. Kyle Smith did not issue a ticket because he did not observe the car moving while the driver was using the phones.
But Smith asked the driver to put the phones in the back seat and move along, because stopping on the shoulder is for emergencies only.
#PokemonDistraction Sergeant Kyle Smith contacted a vehicle on the shoulder yesterday evening. This is what was next to the driver! Playing #PokemonGO with EIGHT (8) phones! Driver agreed to put phones in back seat and continued his commute with 8 less distractions. pic.twitter.com/tgOr16CRlm— Trooper Rick Johnson (@wspd2pio) August 14, 2019