Southern California: It’s pretty much an honor system, but in Hauser Cyn (mile 15) is monitored by the FS and border patrol. If it looks like a dirty hippy convention, BP has been known roust people with high powered lights according to one SD trail angel I knew (now retired). FS only checked a couple days in the last 4 years though. Maybe this year will be different? The only other permit check might be Mt San Jacinto (Idyllwild?) once in a blue moon.
Hikers start dropping out from mile #1 in SoCal (bus stop to San Diego is just off mile 1.5), and the attrition just keeps happening so they aren’t that concerned about the number.
That said if something is strange (like mountain bike poaching), FS will be out checking permits (until the BBQ calls back in town). Bring a full sized copy of your permit.
Sierras northward:
Sierras and central Oregon crossing Highway 20 – this is where the permit checks get serious. Think with the new Oregon restrictions, Jefferson Park will be checked as well.
North of Jeff park is getting near Portlandia day use parks (where thru-hikers look like “stranger danger”), so not sure a permit is really enforceable. Haven’t heard anything about Washington..
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