The state Department of Natural Resources did not fully comply with federal environmental review procedures for a planned, off-road vehicle park in Houston, Minn., according to a federal highway official.

The lapse, explained in a memo obtained by the Star Tribune, happened during the land acquisition phase of the slow-developing project and doesn't disqualify it from continued federal support. But now that the procedural gap has been investigated by the Federal Highway Administration (FHWA), officials are focused on the upcoming possibility of an expensive environmental review that lacks a preordained funding source.

Houston City Council Member Cody Mathers said this week that the developments could galvanize local opposition to a plan long nurtured by DNR and the city as a regional playground for riders of ATVs, side-by-sides, Jeeps and dirt bikes. The DNR has said southeastern Minnesota is bereft of off-highway vehicle trails on public land and City Hall sees the would-be park as a sweetener to the local economy.

"We've learned that some steps were missed,'' Mathers said. "I guess it kind of confirms what some of the opposition has been saying.''

Critics say the proposed complex of 7.5 miles of trails and a "rock crawl'' area would invite noise pollution and environmental damage to a delicate, erodible piece of land that includes a rare section of bluff prairie, habitat for timber rattlesnakes and signs of other valuable resources.

Karla Bloem, a naturalist who previously worked at the DNR, said she blew the whistle on the Houston Trail project for what she considers wide-scale environmental neglect. She poured over government documents dating back to the project's origin in 2009, finding that the DNR bought land for the motorized trail complex without first clearing environmental review hurdles tied to the acceptance of grant money from the highway administration.

"This whole thing would have taken an entirely different route if DNR would have coordinated with federal agencies from the start,'' said Bloem, executive director of the International Owl Center in Houston.

Her campaign against Houston Trail is focused on the steeply sloped site, not against ATV riders. Besides ripping the DNR for side-stepping the federal level of environmental review tied to FHWA grant money, she has publicly shamed DNR for ignoring resource-protection concerns voiced by the agency's own field staff.

"This isn't about minor paperwork,'' Bloem said.

One of her examples is a recommendation from Lisa Joyal, DNR's endangered species environmental review coordinator. In 2011, Joyal advised her agency that any off-highway trail planning should completely avoid two areas on the site: A rare native remnant of "dry bedrock bluff prairie'' and a natural forest of red oak, white oak and sugar maples. Nevertheless, Bloem said, the trail complex was designed to tread across both areas.

Bloem is part of a grassroots group in the Houston area that started a "Save our Bluffs'' lawn sign campaign. This summer, the organizers circulated a petition signed by 400 people requesting that the City Council cancel development of Houston Trail. The signatures constituted 59% of the voting population, Bloem has said.

Ben Bergey, acting division director for DNR Parks and Trails, stressed that FHWA's investigation of DNR's compliance determined that the acquisitions of three land parcels for the motorized trails project were "substantially compliant'' with regulations. No adverse environmental impacts resulted because no construction has occurred, the highway administration said.

Bergey described the non-compliance as "minor'' and "procedural.''

A Dec. 8 memo summarizing the FHWA's investigation was circulated by David Scott, FHWA deputy division administrator for Minnesota. The memo, addressed to DNR's grant specialist, Dan Golner, said "MnDNR did not have FHWA approval for early acquisition.''

DNR submitted environmental documents, the memo said. But the documents "were missing coordination with federal resource agencies such as the U.S. Fish and Wildlife Department and the Army Corps of Engineers.''

The memo said that while highway-subsidized projects require certification of federal environmental review, "the FHWA office never received or accepted such a certification from MnDNR.''

In the memo, Scott requested a meeting with the DNR and the Minnesota Department of Transportation's Office of Environmental Stewardship. The purpose will be to determine the appropriate federal level of review "for the potential construction phase'' of Houston Trail.

Bergey of the DNR said one potential outcome could be an agreement that the project needs no further environmental review. But if there are concerns about serious off-roading impacts at the site, the project may warrant a federal Environmental Assessment costing upward of $500,000, Bloem said.

Bergey said it's not clear who would pay for such a review or whether new environmental scrutiny would jeopardize the project.

"We have to let the process and the data speak for where the project will go,'' Bergey said.

Mathers, the City Council member, said there's no way the city could afford to pay for a federal environmental review. There's already concern on the City Council that Houston could be on the hook for about $500,000 in land purchases initially covered by grant money, he said. The tentative budget for constructing trails is in the range of $300,000.