This article provides a brief overview of the history and current state of the Kakkorovsky Botanical Reserve for curly birch, Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti. The reserve was established to conserve the natural stands (populations) that existed in the southern part of the Republic of Karelia (near Vlg. Kakkorovo, on the southwestern shore of Lake Onego). Four periods are conventionally distinguished in the reserve’s history, reflecting the dynamics of its condition over the past nearly 100 years. Curly birch growing there was first mentioned in the late 1930s, and data on the number of trees become available since 1959. Some information is provided on the trees that are part of the natural stand and the plantation established in the early 1960s, which together received the official status of a nature reserve in 1984. It is also noted that illegal logging in the 1990s reduced the number of curly birch trees in the nature reserve dramatically: from the initial 1,500 trees to 297 in 1998, and only about 30 by 2003. It is emphasized that the consequences have not yet been overcome. During the restoration of the reserve in 2005, high-quality planting stock grown from seeds obtained through controlled pollination of locally grown trees was used. However, the results were significantly worse than expected: 20 years after planting, there survived less than 10 % of the 3,500 stock (approximately 250 trees). According to the survey conducted in 2025, this failure was due to a lack of timely and regular maintenance, resulting in curly birch being displaced by other fastgrowing deciduous species, such as aspen, maple, and rowan. The information available from previous research suggests that by the beginning of the 21st century, curly birch in this reserve, as well as in Karelia as a whole, fell under the real threat of extinction, and the task of preserving and restoring its gene pool had become much more challenging. Nevertheless, a valuable part of the total curly birch gene pool has been retained, and its preservation (primarily through the proper organization of the work of botanical reserves, including Kakkorovsky) is an important and pressing task of national significance.