I'm local so thought I'd post here. First, the Highline trail starts at Logan Pass. If you day hike it there are 2 ways to get back to your car. One, you can hike as far as you want and retrace your route. Most people go either to Haystack Butte (about 6 mi r/t) or to Granite Park Chalet (about 15 mi r/t). There is also the option of taking a steep side trail to the Grinnell Glacier overlook which would make the trip about 17 miles. I mention this side trail because there is a significant drop-off at the top.
From the chalet, you can instead take the Loop Trail down to the road (the place where the newlywed pushed her husband) but you don't come out at Logan Pass. This makes the hike shorter (about 11 miles) but you'd have to get on a shuttle or hitchhike back up the road to the Pass.
Literally hundreds of people hike the Highline every day in the summer. It would be very hard to fall, get lost, or encounter a bear without someone finding you quickly. There was a man missing on this trail 2 years ago, but it is widely thought to be a suicide situation. If you scrambled off the trail for some reason, and couldn't yell for help, you'd be a lot harder to find, but the trail itself mostly traverses open areas.
There is no cell service at Logan Pass. However you can get it sometimes at the chalet or encounter a random signal if you are high up.
If Jenn took the Dragons Tail route instead, she would have encountered many people on the first part of the trail that is on the Hidden Lake trail. I don't think she would have gotten lost per se on Dragons Tail but perhaps off route. I wonder also if she decided to continue down to Hidden Lake instead. I know all these areas are being checked. The weather has been good, cold at night and sunny during the day.
IMO.
Hope she is found OK.
