Mileage Run Discussion - Help booking ITA Matrix fare

Having problems booking a quasi-MR/work trip.
SLC-LAX-PDX-SLC
Dep 9/9 ret 9/11

ITA shows I can go 9/9 morning through LAX booking via AS, arr 3 pm
On 9/11 ITA shows a PDX to SLC on DL 6am flight n/s.
Fare is about $387.

SLC-PDX legs are booked as AS flights.

PDX-SLC is booked as DL Flight.

Sort of ugly.

How do I book this one? I've tried Kayak, Expedia, DL and AS sites and it just doesn't work.

Orbitz

Well, that's probably two one-way fares. So use any online travel agency and book the outbound and return separately. If you have trouble getting the connection in LAX, specify each leg of the journey in a multi-city itinerary.

Example:

Ticket #1:

Flight A: SLC-LAX (AS)
Flight B: LAX-PDX (AS)

Ticket #2:

Flight A: PDX-SLC (DL)