NEW YORK, Sept 17, 2009 (AFP) - Ralph Lauren returned to American roots Thursday 17 September at New York Fashion Week with a Spring-Summer 2010 collection celebrating the simple, sun-kissed world of the prairies.

Ralph Lauren catwalk on 17 September in New York Photo : AFP

The veteran US designer, who turns 70 next month and started his global brand four decades ago, enjoyed a standing ovation from an enthusiastic public on the final day of week.

Strutting to banjo and harmonica tunes, models swapped the typical Ralph Lauren country club look for pioneer chic.

Denim reigned, of course, with stone-washed, ripped jeans in salopette form and over-size trousers held up with cowgirl belts.

In contrast with that frontier spirit, striped jackets were exquisitely tailored, some sleeveless.

The fantasy farm girls, their long, mostly blonde hair flowing in the wind, strode down the catwalk wearing felt bowlers or caps to top off the retro look.

In this idealized version of the Midwest, everything came blue, and even evening wear was in denim, albeit under transparent, pearl-bordered muslin jackets.

"I believe in the resilient spirit of America. Hard times seem to sharpen our capacity for idealism and our optimism that tomorrow will be a better day," Lauren said in his program notes.

"I am inspired by the character of the worker, the farmer, the cowboy, the pioneer women of the prairies living authentically through challenging times."

Of course, even in hard times a cowgirl needs to let her hair down and Lauren's collection has the naive, flowery dresses, and tulle skirts they'll need.

Two other classic US designers were to show before the week closed -- Calvin Klein and Tommy Hilfiger.