A marker fixture for attachment to a utility conduit such as a telecommunications cable. The fixture has an extension member with an electronic marker at one end, and is secured at the other end to the cable. The extension member is movable between a retracted position wherein the marker is adjacent an access point and an extended position wherein the marker is distant from the access point. The extension member is preferably biased toward the extended position and releasably secured at the marker end proximate the utility structure. The marker fixtures may be pre-installed on a utility infrastructure. The extension member is loosely secured so that the fixture may be moved around the cable after it has been installed in a trench to lie atop the access point. The low profile and conforming shape of the fixture make it particularly advantageous for pre-installation on flexible cables wound on large reels.