In my search I've now seen a couple of threads and Viron's article regarding tripod orchard ladders. I finally found and purchased one but I thought I'd share some of what I learned about availability in the Portland area.

I wanted an 8' one because it seems like the best balance of portability and reach for my suburban mini orchard. I very likely would have chosen a 7' one instead were the available but they seem to come in even numbered heights.

One thing I wasn't fully prepared for is how wide the base is. Yikes, I'm still looking for a reasonable way to store in in the garage.

I settled on a Tallman do price, avaialability and reputation. Stokes also makes some very nice looking ladders with some additional features, but they apparently have fewer local vendors and are more pricey.

I paid $147 for the last 8' Tallman they had in stock at Stark Street Lawn & Garden. They said they'd be getting more. I could have paid $10 less if I were willing to Capital Hwy or venture out on a weekday. Start Street is open Saturdays.

I got a list of vendors from Tallman (they replied the same day, as did Stokes).

What I learned regarding availability as of 2 weeks ago:

Stokes: $206 at Horizon for an 8' ladder. can transfer to Vancouver store.

1 in stock at Tigard store
1 in stock Milwaukie

Tallman:
Rain or Shine - NE Airport Way (503) 255-1981 8' tallman $192 in stock
O'Neills Tools - NE Glisan (503) 254-6805 $137 aluminum 8-5 M-F
Parkrose Hardware - NE Sandy Blvd (503) 256-3103 could order 8', 10' is $189
Simplot Partners - NE Mark (503) 262-0475
Stark Street Lawn & Garden - SE Stark (503) 255-5393 $147 8-6M-F, 8-5S
Teufel Nursery - NW Barnes Rd (503) 646-1111 *didn't call, retail store relocating.
Tree Tools - SW Capitol Hwy (503) 943-6680 $138 5:30 F, 10-4 Sat