A quick search of my notes, produced the following results for 37" tire options:
Hankook's DynaPro M/T is available in 37 x 12.50R18D (#3415), has above average performance for a mud tire in all situations except ice, which can be remedied with good siping.
Cooper makes a Discoverer STT PRO in 37x12.50 and 37x13.50 for 17” and 20” wheels. The narrower in 20” has an E load rating, but only D on the 17” wheel. The 13.50 is E for both wheels. (#3750)
Maxxis Trepador TL30026000 has a three ply sidewall and is rated at #3525 in a 37x12.50R17D. It has a six ply main tread (M8060) and is made in Taiwan.
Nitto has a Trail Grappler MT in 37 x 12.50R20E, may reduce sidewall flex if loaded heavy or when towing. (#3750)
A 37” KM2 (17” - 20” wheel) can hold upto #3525 (17”
, good overall, needs siping for snow/ice.
Discover S/T Maxx is available in 37x12.50R17LT(D), 3 ply sidewall, M+S, studable (#3525)
Toyo Mud Terrain in 37x12.50R20E: #1930 (25 psi), #2225 (30 psi), #2470 (35 psi), #2705 (40 psi), #2925 (45 psi), #3085 (50 psi), #3335 (55 psi), #3525 (60 psi), #3750 (65 psi)
Toyo Mud Terrain in 37X12.50R18E: #2095 (25 psi), #2395 (30 psi), #2680 (35 psi), #2915 (40 psi), #3150 (45 psi), #3415 (50 psi), #3590 (55 psi), #3795 (60 psi), #3970 (65 psi)