Depends on how rough those gravel sections are. The Hutchinson Intensives in 700x 25 are the most durable in my experience. I've been through 3 sets of Fusions over the last 4 years as well as the Intensives; I'd choose the latter if it's hardpack gravel or hilly with loose corners. Otherwise, the Stans CX tire, which is a semi-slick would do the trick as long as your bike has the clearance eg a cyclocross bike.
Choices are still rather limited.
For mixed gravel rides with little rough stuff on the N Island, I've mostly been using tubs---27mm Vittoria Pave which fit into my Neil Pryde Alize quite nicely. For all others, I use the cx bike with clinchers.