UST: U.S. Treaties and Other International Agreements (1950-1984). S 9.12 in US Docs.
TIAS: Treaties and Other International Acts Series S 9.10, also in pdf on State Department site (including more recent than published in print). Note the new numbering system on the State Department site. State Department information on the publication delays and publication on the web.
Statutes at Large (Before 1950) AE 2.111
PDF Images of the official publications are available on Hein Online.
State Department Office of the Legal Adviser for Treaty Affairs
USDA Foreign Agricultural Service (trade agreements)
Office of the US Trade Representative (trade agreements: WTO, multilateral, free trade agreements, bilateral)
Trade Compliance Center (trade agreements)
U.S. Income Tax Treaties (IRS)
Treaties in Force (State Department publication): UST, TIAS, UNTS, Stat. citations. Available online on the State Department website and on Hein Online. Bilateral treaties are listed by country, multilateral treaties by subject. The version on the State Department website includes links to depositaries with treaty text.
Guide to United States Treaties in Force: UST, TIAS, UNT, Kav citations. KZ 235 .G85 in USDOCS-REF. Also on Hein Online. Includes Current Treaty Actions supplement, Lists of Treaties no longer in Treaties in Force, and pending and unrecorded treaties. There are country and subject lists of both bilateral and multilateral treaties and a chronological index to multilateral treaties.
U.S. Treaty Index and Current Treaty Index (Kavass): S9.12/2 and S 9.11/2 in USDOCS-REF. An index of all treaties and international agreements from 1776-2002 (with 2012 revision), chronological, by number, by country, and by subject. Updated and supplemented by the Current Treaty Index. Current Treaty Index and other treaty indexes are available on Hein Online.
Kavass numbered treaties are not yet published as TIAS slip treaties. Use KAV numbers to find in Hein Online or with Current Treaty Index.
Treaties and Agreements Library:
Hein Online also has Statutes at Large for U.S. treaties prior to 1950.
Hein Online's Immigration Law & Policy in the US Library includes the multi-volume set Extradition Laws and Treaties of the US.
Westlaw has United States Treaties and Other International Agreements and International Legal Materials.
Lexis has U.S. Treaties, U.S. Treaties in Force, the USCS International Conventions volume (with annotations and history for major U.S. treaties), and Tax Analysts Tax Treaties.