I will update this periodically listed in alphabetic order and will add links to their home pages later, if they have one. There has to be a bunch missing but the list is pretty long already!

If you see any missing brands or know the home page for one that isn't shown or info that is incorrect, post it below and I will add it to the list. Please don't guess on this. Only give me info that you know to be correct first hand. I will keep a question mark after an item that is a guess or that I am not 100% sure on.

My understanding is that it has been many decades since any decent optical glass was manufactured in the USA for consumer sporting optics. If you can find a reliable source that says otherwise, please let us know.

Count -- Brand / Owned By -- Web Site -- Made in / With
1 -- Aimpoint -- www.aimpoint.com -- Sweden
2 -- Alpen -- ? -- ?
3 -- ATN -- www.atncorp.com -- China?
4 -- Barska -- www.barska.com -- Russia
5 -- Brand / Owned By -- Web Site -- Made Where?
6 -- Brunton -- ? -- ?
7 -- BSA -- www.bsaoptics.com -- Chna?
8 -- B-Square -- ? -- ?
9 -- Burris -- www.burrisoptics.com -- Japanese glass / built USA, Low end Phillipines and?
10 -- Bushnell -- www.Bushnell.com -- Japan - low end Korea & China
11 -- Carl Zeiss Optronics -- www.hudisco.com -- Germany?
12 -- Clearidge -- www.clearidgeoptics.com -- Japan and?
13 -- Countersniper -- www.countersniperoptics.com -- China
14 -- Dark Ops -- ? -- ?
15 -- Docter -- ? -- Germany
16 -- Elcan -- www.elcansportingoptics.com -- Some Canadian, Germany?
17 -- Eotech -- www.eotech-inc.com -- ?
18 -- Hawke -- ? -- England design build China and Japan
19 -- Horus -- ? -- Japan? China?
20 -- Insight -- ? -- ?
21 -- IOR Valdada -- www.valdada.com -- Romania
22 -- Kahles -- www.kahles.at -- Austria?
23 -- Konus -- http://www.konususa.com/ -- China?
24 -- Kruger -- ? -- >
25 -- Leapers -- http://www.leapers.com -- China?
26 -- Leatherwood / Hi-Lux -- http://www.leatherwoodoptics.com -- China
27 -- Leica -- http://en.leica-camera.com -- Germany
28 -- Leupold -- www.Leupold.com -- High end Assembled in USA Japanese glass - low end made offshore in? Spotters - Korea
29 -- Meopta -- www.Meopta.com -- Czech Republic
30 -- Meprolight -- www.meprolight.com -- ?
31 -- Millett -- www.millettsights.com -- China
32 -- Mueller -- www.muelleroptics.com -- China
33 -- NCStar -- http://www.ncstar.com -- China
34 -- Nightforce -- www.NightforceOptics.com -- Compacts made in USA with Japanese Glass, NXS and Benchrest assembled in USA from Japanese components
35 -- Nikko Sterling -- www.nikkostirling.com -- ?
36 -- Nikon -- www.NikonUSA.com -- Japan and Phillipines
37 -- Nitrex -- ? -- ?
38 -- Osprey -- www.osprey-optics.com -- ?
39 -- Pentax -- www.pentaxsportoptics.com -- Japan and?
40 -- Premier Reticles -- ? -- Germany? USA? Glass from?
41 -- Pulsar -- ? -- ?
42 -- Redfield (Leupold owned) -- www.redfield.com -- Leupold Owned, Japanese Glass, assembled in USA?
43 -- Safariland -- ? -- ?
44 -- Schmidt & Bender -- www.schmidtbender.com -- Germany?
45 -- Sightmark -- http://www.sightmark.com/ -- ?
46 -- Sightron -- www.Sightron.com -- Japan and?
47 -- Simmons -- http://www.simmonsoptics.com/ -- Owned by Bushnell - Made in China
48 -- Super Sniper -- www.swfa.com -- Japan - Built for SWFA by?
49 -- Swarovski -- http://www.swarovskioptik.us/en_us/home -- Austria?
50 -- Swift -- http://www.swift-sportoptics.com -- Korea
51 -- Tasco -- www.tasco.com -- Owned by Bushnell - Made in China
52 -- Trijicon -- www.trijicon.com -- Japanese Glass Built in USA
53 -- Truglo -- www.truglo.com -- China
54 -- U.S. Optics -- www.usoptics.com -- USA (Glass made in Germany?)
55 -- Unertl www.unertloptics.com/ --
56 -- Vixen -- ? -- ?
57 -- Vortex -- http://vortexoptics.com/ -- Phillipines?
58 -- Weaver / ATK -- www.weaveroptics.com -- Japan, some Phillipines 40-44 series
59 -- Yukon -- www.yukonopticsusa.com -- China?
60 -- Zeiss / Conquest -- http://www.zeiss.com/sports -- Germany / Conquest Assembled in USA