Peel away the sun, surf, hula and flower garlands in Hawaii, and you find cowboys – and Spam – embedded in the lifestyle. I had known about the paniolo, the famous Hawaiian cowboys, and had wanted to ride with them for more than 20 years. But the reverence for canned processed pig parts came as a surprise.

There are only two directions on Hawaii – towards the sea (makai) or towards the mountains (mauka). As you head up the volcano, the land becomes temperate, the breezes sweet and the lush pasturelands a bright electric green.

I rented a studio on Maui in Paia, an old sugar plantation town on the surfers' mecca of the north shore. Paia is well placed at the seashore end of Baldwin Avenue, which climbs 1,500ft to the cowboy town Makawao. Here I met Peter Baldwin, patriarch of Maui's most powerful family, who took me into the world of the paniolo. He told me that Hawaii had cowboys long before Texas or Wyoming. Cattle and horses were given to King Kamehameha at the end of the 18th century. Within 20 years, thousands of feral longhorn cattle rampaged across the islands, destroying crops. In 1830, the king invited three Californian vaqueros to teach the Hawaiians to ride and herd the cattle. Españols became paniolo. The vaqueros also left their guitars, and the Hawaiians found their own way to play them, a sound that, along with the slide guitar, exploded on to the American scene the following century.

Baldwin used to be president of the 32,000-acre Haleakala Ranch until he bought 800 acres which became Piiholo Ranch to raise Corriente cattle, fast wiry steers ideal for competitive roping, his passion. I watched a practice session at his ranch, two men racing after a steer fizzing out of its chute, one to lasso the head, the other the heels. Ever since three Hawaiian roughriders beat the Americans at the Cheyenne Rodeo in 1908, they have been proud of their skills with the kaula 'ili, the Hawaiian lasso.

I went for a ride across Baldwin's ranch, across the bright green kikuyu and pangola grass and up Piiholo Hill with a view right across central Maui and the western volcano, with the white surf-fringed beaches below. Pony Express does horse rides through Haleakala Ranch. I chose to go with them on the trail of dreams, a ride into Haleakala's crater, one of the world's most spiritual places – Hawaiian priests came up here to worship the demigod Maui and Pele the fire goddess.

Riding 2,500ft down into the crater on horseback is like riding on the moon, a wilderness punctuated with rusty cinder cones and volcanic vents. White waves of cloud-surf pour through two gaps in the crater rim.

Finally, Hawaii as the world's Spam epicentre? Along with pineapple, Spam is central to Hawaiian cuisine. Polynesians are generously built people, but Spam pushes many into sumo size. It comes in bizarre combos like Spam-flavoured macadamia nuts or musubi, which is Spam sushi – a white rice-ball with a slice of cooked Spam across the top tied together with nori, Japanese sushi seaweed. The perfect yin and yang, it is an edible oxymoron, the healthy rice and seaweed grappling with the work of the devil. Apparently, it's one of President Obama's favourite foods.

• Virgin Atlantic (virgin-atlantic.com) has returns to San Francisco from £534, and Continental Airlines (continental.com) flies onward to Kahului airport from £395 return. Continental also flies from Heathrow to Kahului from £820 return. A one-hour ride with Piiholo Ranch (piiholo.com) costs $75, and Pony Express (ponyexpresstours.com) offers four-hour rides into the crater for $182 plus tax. Rent a studio in Paia for a week from $815 through VRBO or Vacation Rentals By Owner (vrbo.com)

• Hank Wangford will join Sandi Toksvig on Radio 4's Excess Baggage at 10am on 23 July