The Marina is open for the 2020 season with restrictions. Slip away to an island retreat and dock at the hottest spot on the Mississippi. The Treasure Island Marina offers 56 transient slips with docking up to 100 feet and 81 seasonal slips. Just one mile north of Lock & Dam No. 3 in the Sturgeon Lake Channel, we are conveniently located whether you venture up river, down river or towards the best gaming and entertainment in Minnesota.