|| align=right | 3.5 km || |-id=241 bgcolor=#fefefe | 45241 || || — || December 5, 1999 || Anderson Mesa || LONEOS || NYS || align=right | 1.7 km || |-id=242 bgcolor=#fefefe | 45242 || || — || December 13, 1999 || Anderson Mesa || LONEOS || V || align=right | 1.5 km || |-id=243 bgcolor=#E9E9E9 | 45243 || || — || December 13, 1999 || Catalina || CSS || — || align=right | 3.0 km || |-id=244 bgcolor=#E9E9E9 | 45244 || || — || December 13, 1999 || Catalina || CSS || — || align=right | 2.8 km || |-id=245 bgcolor=#E9E9E9 | 45245 || || — || December 13, 1999 || Catalina || CSS || — || align=right | 4.8 km || |-id=246 bgcolor=#E9E9E9 | 45246 || || — || December 5, 1999 || Socorro || LINEAR || — || align=right | 4.3 km || |-id=247 bgcolor=#fefefe | 45247 || || — || December 5, 1999 || Socorro || LINEAR || — || align=right | 2.1 km || |-id=248 bgcolor=#E9E9E9 | 45248 || || — || December 5, 1999 || Anderson Mesa || LONEOS || — || align=right | 7.5 km || |-id=249 bgcolor=#E9E9E9 | 45249 || || — || December 7, 1999 || Kitt Peak || Spacewatch || — || align=right | 4.1 km || |-id=250 bgcolor=#E9E9E9 | 45250 || 1999 YJ || — || December 16, 1999 || Socorro || LINEAR || — || align=right | 5.7 km || |-id=251 bgcolor=#FA8072 | 45251 || 1999 YN || — || December 16, 1999 || Socorro || LINEAR || — || align=right | 3.8 km || |-id=252 bgcolor=#E9E9E9 | 45252 || || — || December 16, 1999 || Kitt Peak || Spacewatch || — || align=right | 2.4 km || |-id=253 bgcolor=#E9E9E9 | 45253 || || — || December 28, 1999 || Farpoint || G. Hug, G. Bell || DOR || align=right | 8.1 km || |-id=254 bgcolor=#d6d6d6 | 45254 || || — || December 27, 1999 || Kitt Peak || Spacewatch || THM || align=right | 9.3 km || |-id=255 bgcolor=#d6d6d6 | 45255 || || — || December 31, 1999 || Farpoint || G. Hug, G. Bell || — || align=right | 7.3 km || |-id=256 bgcolor=#fefefe | 45256 || || — || December 31, 1999 || Socorro || LINEAR || PHO || align=right | 3.1 km || |-id=257 bgcolor=#d6d6d6 | 45257 || || — || December 31,