Marquette Mountain Falls, or Lower Carp River Falls, is little more than a set of rapids. There are plenty of rapids along this stretch of Carp River (east of County Road 553), making it hard to pinpoint the named drops, and none of them are terribly impressive. A bike path winds it's way around Marquette Mountain on the north bank and fisherman can usually be seen along the river, especially during the spring.
From the roundabout in Marquette where US-41 turns south along the shoreline drive 1.5 miles south, up the steepening hill. Turn right at Carp River Hill/Cliff Power/Mt Marquette Road and follow the dirt road about .7 miles, sticking to the left of the fork at .6 miles. Park here and follow the path(s) up the river. There are plenty of small rapids along the river if you want to walk all the way to County Road 553, maybe a mile and a half to the west.