A shipment of marijuana valued at roughly $750,000 and filling the back of a full-sized pickup truck was seized by Plymouth police along a busy interstate, and two brothers in the vehicle were arrested, authorities said Tuesday.

The 200 pounds of pot came from South Dakota, where law enforcement on Monday had alerted police in Plymouth that the load was on the way, said police Capt. Jeff Swiatkiewicz.

Drug investigators and police set up surveillance of the marijuana's parking-lot transfer and soon after arrested the brothers, ages 27 and 23, both from Independence, Swiatkiewicz said.

The jail log lists separate addresses for them a mile apart in the northern California city of Chico. They remain jailed pending charges, which Swiatkiewicz said should come Wednesday.

The person who drove the pot shipment to Plymouth has yet to be arrested. Swiatkiewicz said the deliverer "could have been unaware" of the illicit nature of the shipment.

That person's role in the exchange off County Road 6, between Hwy. 55 and I-494, remains under investigation.

Once the pot was handed off, the brothers got on Interstate 394 with their covered flatbed brimming, Swiatkiewicz said.

Officers pulled them over in Minnetonka near the Plymouth Road exit about 1:30 p.m., the captain added.

Swiatkiewicz said he's never heard of such a large drug transaction in the 17 years he's served on the Plymouth police force.

The older brother has had many run-ins with the law since 2003, including two drunken-driving convictions and two drug possession convictions. The younger brother has two minor alcohol violations on his record.