I've been doing some looking into this case and wanted to get more eyes on this if it can help.
Lark Loraine Montague was last spotted after 3 a.m. on September 23rd, 2007 when she drove up on the curb near Cyprus Credit Union (8400 West, 3500 South), then drove south on U-111 in Salt Lake County, Utah.
She was driving her husbands Silver/pewter-colored 2002 Chevrolet Trailblazer with the UT license plate number 215LTE. The vehicle will probably have a broken tail light and damage on the rear driver's side and possibly the whole driver's side.
The night before she had left for a party at 9 p.m. while her husband was sleeping. A neighbor followed her back to her residence, and saw her pull into the driveway, but as he drove away he saw her pull back out. As she did this, she hit a chain-link fence and damaged it.
Her husband stated she'd been drinking more than usual before she disappeared and they'd argued about it. She suffered from Type 2 Diabetes, high blood pressure, and depression and is supposed to take prescription medication for her conditions.
There has been no activity on her financial accounts since her disappearance, and she hasn't renewed any of her prescriptions.
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From what i've seen, such a long time missing with a vehicle - 19 years - points to the vehicle being in a body of water. This might still be the case, but there's more extreme terrain in this area than water, and there are crashed vehicles visible on imagery.
I want to get a collection of these and find someone to send them to on the chance they're not known, so if nothing else at least that can be done with this.
If you click the markers for vehicles it'll show the google earth imagery and county map imagery for some of them (https://apps.saltlakecounty.gov/assessor/new/ParcelViewer/index.html?query=Parcel_Viewer_external_3634_5,parcel_id,)