The Warrenton Horse Show, billed as the "Hunter Show of America," will open Friday and continue through Monday with some of the top thoroughbreds in the country competing for a blue ribbon and a championship.

One of the highlights of the show will be the Virginia Horse Shows Association hunter seat equitation final on Sunday morning. Junior riders have been competing throughout the season to qualify for this event.

Among the entries in the various hunter classes will be NESW, Inc's Get It Straight in the first-year green division with Scott Williamson of Middleburg aboard.

The big bay gelding will be up against Liz Johnson's Magic Man and A.C. Brady's Patriots Way, both ridden by Charlie Weaver of Keswick, Va. Kevin Lenehan of Southern Pines, N.C. also will be riding in the first-year green hunters on Ann Self's Fond Farewell.

In the regular-conformation division, Weaver also will be battling it out for top honors with Lenehan. Weaver will be up on Johnson's Early Light, the chestnut gelding that was horse of the year in 1978. Lenehan will be riding O'Rouke Storage and Transfer's Chadds Ford.

In the regular-working hunter section, Weaver will be up on August A. Busch's bay gelding Ruxton. Joey Darby of Southern Pines has been named to ride two horses for Edward Bulkley: Boren and Peace Murmer.