The road ends here, almost literally. Tashanta is the Russian border post on the Chuysky Trakt, a tiny settlement high in the dry southeast corner of the Altai Republic at about two thousand metres, where the highway that began far back in Biysk reaches the Mongolian frontier. There is not much more to it than customs buildings, a few houses and a very big sky. Kosh-Agach, the nearest town of any size, lies a long drive back to the northwest, so fuel and supplies belong to that town, not here.
The ride up is among the most dramatic in southern Siberia. After Kosh-Agach the road crosses the Chuya steppe, a high, dry basin ringed with snow peaks, where the vegetation turns to short grass and the wind never stops. The tarmac is fairly straight, with long, open stretches, and the real challenge is the weather: crosswinds, sudden cold, and in winter extreme frost. Summer is the sensible season, and even then you should pack warm gear. The light is fierce and clear, with distances that deceive, and the peaks of the Southern Chuya range stand white above the steppe.
The border here is a controlled area, and visiting requires the right documents and permission, which change over time, so check current rules before you set out. Treat the border post with respect and avoid photographing military or customs installations. The crossing into Mongolia lies beyond, in a region of high plateaus and nomadic herders, where Kazakh and Mongolian cultures meet. Until the twentieth century this was the old caravan route for tea, silk and furs, and the Chuya steppe has seen travellers for thousands of years.
Nature is stark and beautiful. The steppe is home to marmots, hawks, falcons and steppe eagles, and in the nearby mountains live argali sheep and snow leopards, though a rider is very unlikely to meet any of them. Salt lakes and streams dot the basin, and the soil is stony and pale. At night, the sky is crowded with stars, and the cold is sharp.
Bring more fuel than you think you need, plus water, food and warm layers, and tell someone your plan. Mobile coverage is poor, and help is far away. The reward is the feeling of having reached an actual edge.