Leland Silliman

American author born 1906? I don't know very much about this author. He wrote a number of children's books aimed mainly at boys and featuring 'boyish' activities such as baseball, american football and camping, etc. He wrote a short horse series of the 'ranching' type which was no doubt enjoyed by many girls too! As far as I know this was his only foray into equine territory.

Golden Cloud Series:

1) GOLDEN CLOUD: PALOMINO OF SUNSET HILL
(WINSTON [USA] 1950)
ILLUSTRATED BY PERS CROWELL
Reprinted in paperback a number of times by Scholastic
SUMMARY: Whilst working on a ranch Orin reluctantly falls in love with the beautiful palomino mare Golden Cloud - reluctantly because the horse is promised to someone else...

2) GOLDEN CLOUD IN TEXAS
(WINSTON [USA] 1953)
ILLUSTRATED BY PERS CROWELL

Collector's Info:
The books are quite easy to find in the USA, with the second one slightly less common. Harder to get hold of elsewhere.